News Article | November 15, 2016
Transfer printing microstructures onto novel hydrogel interfaces and customised composite electrodes could increase the compatibility and information transfer between body tissue and electronic devices. Implantable devices such as pacemakers, cochlear implants, and deep brain stimulation devices enhance the quality of life for many people. Improving the integration of such devices with the body could enable the next generation of brain-machine interfaces (such as, implantable devices that can record and modulate neurological function in vivo) to monitor physiology, detect disease, and deploy bioelectronic medicines.1 Current implantable devices are not well matched with body tissues in terms of their mechanical, chemical, and physical properties. The tissues that may be excited or interrogated by implants (e.g., brain, spinal cord, or cardiac muscle) are mechanically compliant, curvilinear, and perform their functions by modulating the flow of ions.2 Conversely, most implantable silicon-based devices are mechanically rigid, and use electrons or holes as their primary information currency. These elements of mismatch reduce the overall performance of current implantable technology in three ways (see Table 1). First, the difference in mechanical properties (i.e., the elasticity) can cause local tissue damage that compromises the fidelity of measurements. Second, changing between ionic and electronic transduction decreases the information density and stimulation specificity. Finally, the materials that are typically used in microelectronic implants are susceptible to rapid protein adsorption, which initiates a cascade of local inflammation and scarring. The biological response to the presence of foreign material (such as an implant) can also compromise bidirectional communication. Table 1.The fundamental physical asymmetries that exist between excitable tissue in the nervous system and implantable, silicon-based biosensors (e.g., brain-machine interfaces and other bioelectronic devices). Biomimetic interfaces can potentially bridge the incongruities between natural tissue and synthetic materials, thereby improving overall device performance. PNI: Peripheral nerve interface. ESi: Young's modulus of silicon. PNS: Peripheral nervous system. G': Storage modulus of a polymer or tissue. ECM: Extracellular matrix. γH2O - material: Residual energy at the interface between water and a given material. CPs: Conducting polymers. Pt: Platinum. Mechanically compliant electronics are ideal for neural interfaces because they can conformably meld with excitable tissue.3 Flexible devices can also reduce the inflammatory responses that are associated with a mechanical mismatch at the tissue-device interface.4 Integrating electronics with hydrogel-based materials may harmonize their mismatch (see Figure 1).5 Fabricating such devices is challenging, however, as the processes involved require elevated temperatures, high vacuum, and exotic solvents. Such conditions are fundamentally incompatible with flexible swollen hydrogels. Transfer printing, in which a structure is printed onto a substrate and then lifted onto the hydrogel, is one technique that may be used to integrate large-area-format microelectronic devices with flexible substrates such as ultracompliant swollen hydrogels.6 There are, however, a number of technical challenges associated with this methodology. These challenges include the appropriate selection of donor substrate materials and target substrates, and reduced adhesion in hydrated environments. Figure 1. The relative Young's moduli of a range of biological and electronic materials. Excitable tissues in the nervous and cardiac systems exhibit significantly smaller Young's moduli than materials that are commonly used in microelectronic fabrication. The ideal bioelectronic interface would integrate materials commonly used in microelectronic fabrication with hydrogel-based materials that can match the mechanical properties of the brain, peripheral nervous system (PNS), and even cardiac tissue. PDMS: Polydimethylsiloxane. In our work, we use a novel technique to transfer print metallic microstructures onto ultracompliant hydrogel-based target substrates that incorporate bio-inspired chemistries to promote adhesion to inorganic materials in wet environments (i.e., the human body).7, 8 To achieve this, we have designed swollen hydrogels that include catechol, a compound that is present in marine organisms, to promote surface adhesion in wet environments.9 These hydrogels exhibit storage moduli on the order of 10kPa, which is comparable to those of many excitable tissues, including cardiac muscle and peripheral nerves.10 Our complementary transfer printing process—illustrated in Figure 2—enables microfabricated structures to be integrated with such bioinspired hydrogels. The key innovation of our process is the use of a selectively removable sacrificial release layer. This temporary release layer is composed of water-soluble poly(acrylic acid) (PAA) film that is crosslinked with divalent cations such as calcium. The film, which is spin-coated on silicon handling wafers, can be selectively dissolved through ion-exchange with aqueous solutions of monovalent cations. Using our method, materials that are commonly used in microelectric fabrication (e.g., metals, oxides, and polymers) can be transfer printed onto hydrated target substrates.11 This technique requires device fabrication and a priori preparation of the hydrogel target substrate. Figure 2. (a) The transfer-printing process. Donor substrates for transfer printing are prepared by (i) spin-coating a sacrificial layer of water-soluble poly(acrylic acid) (PAA) and (ii) crosslinking in an ionized calcium (Ca2+) solution prior to (iii) fabricating gold microelectrodes onto the PAA-Ca2+surfaces. (iv) Adhesive-swollen hydrogel-based target substrates are conformably laminated on the donor substrate surface for five minutes and then (v) removed from the donor substrate in an ionized sodium (Na2+) solution, resulting in the transfer of gold microstructures onto the hydrogel substrate. (vi) An optical micrograph showing a portion of the gold microstructures on the hydrogel substrates. (b) Optical micrographs of gold microelectrode arrays. The hydrogel substrates are cycled between hydrated and dehydrated states, demonstrating robustness in adhesion at the hydrogel-electrode interface. (c) Resistance values for gold microelectrodes indicate that the electrical conductivity is preserved for five hydration/dehydration cycles. Reproduced from Wu et al. (a) The transfer-printing process. Donor substrates for transfer printing are prepared by (i) spin-coating a sacrificial layer of water-soluble poly(acrylic acid) (PAA) and (ii) crosslinking in an ionized calcium (Ca) solution prior to (iii) fabricating gold microelectrodes onto the PAA-Casurfaces. (iv) Adhesive-swollen hydrogel-based target substrates are conformably laminated on the donor substrate surface for five minutes and then (v) removed from the donor substrate in an ionized sodium (Na) solution, resulting in the transfer of gold microstructures onto the hydrogel substrate. (vi) An optical micrograph showing a portion of the gold microstructures on the hydrogel substrates. (b) Optical micrographs of gold microelectrode arrays. The hydrogel substrates are cycled between hydrated and dehydrated states, demonstrating robustness in adhesion at the hydrogel-electrode interface. (c) Resistance values for gold microelectrodes indicate that the electrical conductivity is preserved for five hydration/dehydration cycles. Reproduced from Wu et al. 7 with permission. Copyright American Chemical Society 2016. We have also developed a next-generation transfer printing process that enables catechol-bearing hydrogels to be formed, by rapid in-situ gelation, directly on top of pre-microfabricated structures that are laminated to a water-soluble sacrificial layer. Our gelation-assisted transfer printing method enables three processes (i.e., gel formation, the adhesion of microfabricated structures to target hydrogel substrates, and dissolution of the underlying PAA-based sacrificial layer) to take place simultaneously. This technique improves the prospects for bulk wafer processing and could enable the development of efficient manufacturing techniques for integrating microelectrode arrays with ultracompliant adhesive hydrogel-based substrates. This combination of target substrate composition and transfer printing is broadly generalizable and applicable for bioelectronic devices ranging from brain-machine interfaces to smart contact lenses.12, 13 The deterministic design of composite electrode materials represents one strategy by which we hope to harmonize the mechanical asymmetries between the natural nervous system and implanted devices. Customized flexible materials must allow for the efficient transduction of information between neurons and biosensors. We plotted a number of existing electrode materials as a function of their Young's modulus and charge-injection capacity (Q )—both key figures of merit in stimulation electrode materials—to illustrate their suitability for this application: see Figure 3. The ideal material would have mechanical properties that approach those of excitable tissue (i.e., a Young's modulus less than 10kPa) and arbitrarily high Q values. These characteristics reduce the area that is required for stimulation and therefore increase the spatial resolution of electrode arrays. Even elastomeric electrode materials would be able to accommodate the large strains that are often observed when flexible electronic devices are implanted in vivo. Many existing electrode materials are both rigid and exhibit Q values that are an order of magnitude smaller than many conducting polymers, such as poly(3,4-ethylenedioxythiophene) and polyaniline. Conjugated (conducting) polymers conduct both ions and electrons and are therefore attractive coating materials for implantable biosensors.14 Conducting polymers are often rigid and brittle, however, with Young's moduli approaching 10GPa. Based on these configurations, we have designed intrinsically flexible conducting polymers based on polyaniline that can preserve the native electronic properties typical of such materials and exhibit intrinsic elastomeric properties (see Figure 3).15 The key discovery that enabled this breakthrough is the use of block-copolymer templates to control the morphology of in-situ polyaniline synthesis. The result is an elastomeric conducting polymer that can facilitate charge injection and improve the overall performance of flexible bioelectronic interfaces. Elastomeric conducting polymers show great promise as coating materials for metallic leads. Such coatings could accommodate the large strains that may be experienced by implantable microelectrode arrays, thereby improving their reliability. We are particularly interested in evaluating the in-vivo performance of these materials to identify the fundamental limits of electrode size. A 50-fold improvement in Q could reduce the characteristic length scale of electrodes from 50μm to less than 10μm, thereby leading to enhanced specificity of neuron stimulation. Figure 3. The Young's moduli and charge-injection characteristics of a range of organic and inorganic electrode materials. The charge-injection mechanism of each material is color-coded: green for capacitive; dark blue for pseudo-capacitive; and light blue for faradaic. Next-generation electrode materials must exhibit unique combinations of physical properties including elastomeric mechanical behavior (to accommodate flexibility) and efficient charge injection (to facilitate electrode miniaturization). Common electrode materials, such as Pt, titanium nitride (TiN), and iridium oxide (IrO ) can inject charge efficiently, but are not elastomeric. Organic electrode materials such as poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy), and single-walled carbon nanotubes (SWNT) offer improved charge-injection performance, but have rigid mechanical properties. Next-generation materials may include templated conducting polymers, such as polyaniline (PANI), that exhibit high charge-injection capacities in combination with elastomeric mechanical properties. In summary, we have developed a transfer-printing process that enables electronic microstructures to be printed directly onto flexible hydrogel substrates. Furthermore, we have shown that the resulting microelectrode arrays are robust enough to maintain their electronic properties after five cycles of hydration and subsequent dehydration. Bioelectronic interfaces that can transduce information between tissues and devices will have exceptional utility in future biomedical applications, and should find application in both diagnostic tools and therapeutic modalities. Improving the reliability of such interfaces to achieve these aims requires advances in material synthesis and microfabrication techniques. Additionally, developments in these areas will also help to harmonize the intrinsic physical asymmetries between the natural and synthetic domains. We believe that next-generation bioelectronic interfaces will seamlessly meld tissues and devices by incorporating novel biomimetic materials, non-conventional microelectronic fabrication techniques, and comprehensive device integration strategies. In the next stage of our work, we plan to design and fabricate fully packaged and ultra-compliant adhesive microelectrode arrays for in vivo recording. The authors acknowledge financial support from the Carnegie Mellon Lian Ji Dan Fellowship, the Defense Advanced Research Projects Agency (grant D14AP00040), the National Science Foundation (grant DMR 1501324), and the National Institutes of Health (grant R21EB015165). Department of Materials Science and Engineering Carnegie Mellon University (CMU) Pittsburgh, United States Wei-Chen Huang is a postdoctoral researcher. She received her PhD in materials science and engineering from the National Chiao Tung University of Taiwan in 2015. Her current research interests include the design of biomimetic materials and advanced fabrication processes for the development of ultra-compliant implanted electronics, and nanoparticles for neural interface technology, drug delivery, bioimaging, and tissue engineering. Haosheng Wu received his BSc degree in applied physics from Southeast University, China. He subsequently received MSc and PhD degrees in materials science and engineering from CMU, under the supervision of Christopher Bettinger. His research interests include flexible organic-inorganic hybrid electronics, micro- and nano-fabrication techniques, and novel functional interfaces and devices. Christopher J. Bettinger is an associate professor. He directs the Biomaterials-based Microsystems and Electronics laboratory, which is broadly interested in the design of novel materials and interfaces to integrate medical devices with the human body. 2. Y. Kajikawa, C. E. Schroeder, How local Is the local field potential?, Neuron 72, p. 847-858, 2011. 3. D.-H. Kim, J. Viventi, J. J. Amsden, J. Xiao, L. Vigeland, Y.-S. Kim, J. A. Blanco, et al., Dissolvable films of silk fibroin for ultrathin conformal bio-integrated electronics, Nat. Mater. 9, p. 511-517, 2010. 6. M. A. Meitl, Z.-T. Zhu, V. Kumar, K. J. Lee, X. Feng, Y. Y. Huang, I. Adesida, R. G. Nuzzo, J. A. Rogers, Transfer printing by kinetic control of adhesion to an elastomeric stamp, Nat. Mater. 5, p. 33-38, 2006. 7. H. Wu, V. Sariola, C. Zhu, J. Zhao, M. Sitti, C. J. Bettinger, Transfer printing of metallic microstructures on adhesion-promoting hydrogel substrates, Adv. Mater. 27, p. 3398-3404, 2015. 10. J. T. Maikos, R. A. I. Elias, D. I. Shreiber, Mechanical properties of dura mater from the rat brain and spinal cord, J. Neurotrauma 25, p. 38-51, 2008. 14. M. R. Abidian, K. A. Ludwig, T. C. Marzullo, D. C. Martin, D. R. Kipke, Interfacing conducting polymer nanotubes with the central nervous system: chronic neural recording using poly(3,4-ethylenedioxythiophene) nanotubes, Adv. Mater. 21, p. 3764-3770, 2009. 15. H. Ding, M. Zhong, H. Wu, S. Park, J. W. Mohin, L. Klosterman, Z. Yang, et al., Elastomeric conducting polyaniline formed through topological control of molecular templates, ACS Nano 10, p. 5991-5998, 2016.
News Article | September 1, 2016
Home > Press > GrapheneCanada 2016 International Conference: Recent advances in technology developments and business opportunities in graphene commercialization Abstract: The 2nd edition of Graphene & 2D Materials Canada 2016 International Conference & Exhibition (www.graphenecanadaconf.com) will take place in Montreal (Canada): 18-20 October, 2016. Graphene Canada 2016 attractive and promising program features 40 high-level Keynote and Invited speakers from all over the world, with a perfect mixture of fundamental research and industrial perspective. Top industry leaders will discuss recent advances in technology developments and business opportunities in graphene commercialization. Not to be missed: - The plenary session - An industrial forum with focus on Graphene Commercialization (Abalonyx, Alcereco Inc, AMO GmbH, Avanzare, AzTrong Inc, Bosch GmbH, China Innovation Alliance of the Graphene Industry (CGIA), Durham University & Applied Graphene Materials, Fujitsu Laboratories Ltd., Hanwha Techwin, Haydale, IDTechEx, North Carolina Central University & Chaowei Power Ltd, NTNU&CrayoNano, Phantoms Foundation, Southeast University, The Graphene Council, University of Siegen, University of Sunderland and University of Waterloo) - Extensive thematic workshops in parallel (Materials & Devices Characterization, Chemistry, Biosensors & Energy and Electronic Devices) - A significant exhibition (Abalonyx, Go Foundation, Grafoid, Group NanoXplore Inc., Raymor | Nanointegris and Suragus GmbH) The GrapheneCanada 2016 will bring together, from a global perspective, scientists, researchers, end-users, industry, policy makers and investors in an environment of cooperation and sharing towards the challenges of Graphene commercialization. Organisers: Phantoms Foundation www.phantomsnet.net Catalan Institute of Nanoscience and Nanotechnology - ICN2 (Spain) | CEMES/CNRS (France) | GO Foundation (Canada) | Grafoid Inc (Canada) | Graphene Labs - IIT (Italy) | McGill University (Canada) | Texas Instruments (USA) | Université Catholique de Louvain (Belgium) | Université de Montreal (Canada) For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Shih C.,University of Connecticut |
Han S.,Southeast University
57th ISA Power Industry Division Symposium 2014, POWID 2014 - Power Generation: Instrumentation and Control Solutions for Today's Industry Challenges | Year: 2014
Evaluating wind farm effective loading carrying capacity (ELCC) is an important task in planning wind power systems. A model based on wind turbine generator was proposed to identify wind farm capacity in the presence loading to grid. When the additional load was added, the additional wind farm capacity will be installed to maintain the same reliability. The wind farm also combines an energy storage device that smooths the power output curve. The smooth power output will contribute to effective loading carrying capacity. Further, optimal installed wind farm capacity that maximizes the effect of the installed wind farm load on the grid, including reliability considerations, will be described in this paper. Copyright © (2014) by International Society of Automation - ISA All rights reserved.
News Article | December 1, 2016
Ingelheim, Germany and Nanjing China, 01-Dec-2016 — /EuropaWire/ — Boehringer Ingelheim and China Southeast University Institute of Life Sciences today announced the start of a joint research project to develop new treatment approaches for hearing loss through regeneration of hair cells from inner ear stem cells. The new collaboration combines the expertise of Professor Renjie Chai, one of the worldwide leaders in the field of hearing loss, with Boehringer Ingelheim’s expertise in drug discovery and clinical development to pave the way for the development of much needed new treatment options for this condition. According to WHO data, over 360 million people live with disabling hearing loss, of which 32 million are children under15 years old. The prevalence of hearing loss increases with age and has a serious impact on the elderly by diminishing their ability to communicate and affecting their daily quality of life. A dramatic increase in frequency of the condition is predicted as a result of worldwide aging populations. Patients with hearing loss usually have degeneration of inner ear hair cells. There is no effective treatment that could restore hearing loss. “Professor Renjie Chai and his team are among the world leaders in this emerging research area. We are excited about initiating this collaboration, which is an important next step towards a new focus area for our research and development and our first human pharma research collaboration in China,” said Clive R. Wood, Ph.D., Senior Corporate Vice President, Discovery Research at Boehringer Ingelheim. “This is our second collaboration in hearing loss, one of the focus areas of our Research Beyond Borders initiative. It is an outstanding example of how this unique initiative will boost our R&D by partnering with the most innovative scientists working at the forefront of biomedical research.” The new research collaboration in hearing loss is an initiative of Boehringer Ingelheim’s newly established organisation Research Beyond Borders (RBB). It complements a research collaboration with Kyoto University initiated earlier this year that focuses on utilising findings on hair cell regeneration in birds. Through the collaboration with China Southeast University, Boehringer Ingelheim will investigate key signaling pathways and proteins involved in regeneration in the inner ear to develop a drug discovery strategy to target hair cell regeneration and ultimately address the unmet medical need in hearing loss via regenerative medicine approaches. Dr. Wei Xie, Dean of China Southeast University Institute of Life Sciences commented: “Through this joint project with Boehringer Ingelheim, a world leading innovative pharmaceutical company, we wish to further promote scientific development in the field of hair cell regeneration, and to accelerate the translation of basic science to clinical applications. The current collaboration will demonstrate the regulation mechanism of inner ear stem cells, and we hope to develop insights for targeting the key pathways via small molecule compounds together with Boehringer Ingelheim.” RBB is one of the pillars of Boehringer Ingelheim’s R&D strategy. It complements the company’s five core therapeutic areas (cardiometabolic, respiratory, immunology, oncology and central nervous system) by exploring emerging science, disease areas and technology. It will contribute new innovation opportunities within and beyond the core therapeutic areas and ensure early entry for Boehringer Ingelheim in the next big innovation waves in in biomedical research. RBB is currently focusing on the areas of regenerative medicine, the microbiome and new technologies such as gene therapy. Asia is rapidly becoming an innovation a hot spot in biomedical research and has gained a leading position in regenerative medicine research. Boehringer Ingelheim is thus expanding its activities in this region and looking for more partnering opportunities. By combining a focus on cutting-edge science with a long-term view the company aspires to develop the next generation of medical breakthroughs to improve the lives of patients with high unmet medical needs. About Research Beyond Borders (RBB) RBB is a global research division newly established within Boehringer Ingelheim’s discovery research organization. RBB supports discovery research activities for the development of pharmaceutical products in Boehringer Ingelheim’s key therapeutic areas (cardiometabolic, respiratory, immunology, oncology, central nervous system) as well as disease areas with considerable unmet needs, such as sensorineural hearing loss, by identifying cutting edge medical and scientific fields and technologies in a timely and efficient manner through the discovery of new scientific results and technologies. Boehringer Ingelheim Boehringer Ingelheim is one of the world’s 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, Boehringer Ingelheim operates globally through 145 affiliates and a total of some 47,500 employees. The focus of the family-owned company, founded in 1885, is on researching, developing, manufacturing and marketing new medications of high therapeutic value for human and veterinary medicine. Social responsibility is an important element of the corporate culture at Boehringer Ingelheim. This includes worldwide involvement in social projects through, for example, the initiative “Making More Health” while also caring for employees. Respect, equal opportunity and reconciling career and family form the foundation of mutual cooperation. The company also focuses on environmental protection and sustainability in everything it does. In 2015, Boehringer Ingelheim achieved net sales of about 14.8 billion euros. R&D expenditure corresponds to 20.3 per cent of net sales. For more information please visit www.boehringer-ingelheim.com About China Southeast University Southeast University (SEU) is one of the national key universities administered directly under the Central Government and the Ministry of Education of China. Southeast University has become a comprehensive and research-oriented university featuring the coordinated development of such multi-disciplines as science, engineering, medicine, literature, law, philosophy, education, economics, management, art, etc., with engineering as its focus. The university boasts a high-level faculty of over 2,700 full-time teachers, including 1800 full or associate professors, 835 doctoral supervisors, 1,889 supervisors for masters, 13 academicians of the Chinese Academy of Sciences and Academy of Engineering. At present, it has an enrollment of over 30,000 full-time students, including 14,440 postgraduate students; it also has over 3,300 on-the-job master’s degree candidates. The university now comprises 29 schools or departments with 75 undergraduate disciplines in all.
News Article | August 25, 2016
Multidrug resistance (MDR) is the mechanism by which many cancers develop resistance to chemotherapy drugs, resulting in minimal cell death and the expansion of drug-resistant tumors. To address the problem of resistance, researchers have developed nanoparticles that simultaneously deliver chemotherapy drugs to tumors and inhibit the MDR proteins that pump the therapeutic drugs out of the cell. The process is known as chemosensitization, as blocking this resistance renders the tumor highly sensitive to the cancer-killing chemotherapy. MDR is a major factor in the failure of many chemotherapy drugs. The problem affects the treatment of a wide range of blood cancers and solid tumors, including breast, ovarian, lung, and colon cancers. Researchers at the National Institute of Biomedical Imaging and Bioengineering (NIBIB), a part of the National Institutes of Health (NIH), are engineering multi-component nanoparticles that significantly enhance the killing of cancer cells. The results of their experiments are reported in recent articles in Scientific Reports and Applied Materials & Interfaces. The work is led by senior author Xiaoyuan (Shawn) Chen, Ph.D., Senior Investigator, Laboratory of Molecular Imaging and Nanomedicine, NIBIB. His collaborators include scientists and engineers in China at Southeast University, Shenzhen University, Guangxi Medical University, and Shanghai Jiao Tong University, in addition to chemical engineers at the University of Leeds, United Kingdom. Says Chen about his substantial network of collaborators, “success in this medically important endeavor has required a team with a wide range of expertise to engineer nanoparticles that survive the journey to the tumor site, enter the tumor, and successfully perform the multiple functions for chemosensitization.” Targeting Multidrug-resistant Breast Cancer The two publications report on the engineering of two separate nanoparticles that test different strategies for achieving chemosensitization of cancer cells. The first targets MDR breast cancer. The engineered round nanoparticle is made of several layers. The center of the particle is loaded with the anti-cancer drug doxorubicin. The drug is surrounded by a water-repelling (hydrophobic) capsule to protect it from the watery environment when the particle is injected into the circulatory system of an experimental animal or individual with cancer. The particle has several outer layers with different properties. One of the outermost components, a molecule called PEG, is hydrophilic (mixes with water) and helps the particle move through the bloodstream until it encounters the breast tumor cells. Another component on the surface of the particle, biotin, functions to bind specifically to the cancer cells and helps the drug-carrying nanoparticle to enter the cell. Once inside the breast cancer cell, a fourth component called curcumin, which is intertwined with the doxorubicin center, is released along with the doxorubicin. The curcumin is the component that blocks the cell machinery that would pump the doxorubicin out of the cell. Without the ability to pump out the medicine, the cell is exposed to very high concentration of doxorubicin, which kills the breast cancer cells. Experiments in mice demonstrated that the multi-component nanoparticles were effective at targeting breast tumor cells—accumulating at much higher concentrations in the cancer cells than in the other mouse tissues. Histology showed that the treated mice had a great reduction in cancer cell density in the tumor tissue compared with mice given saline or doxorubicin alone (not integrated into a nanoparticle). Complete analysis of the treated mice confirmed that the nanoparticle efficiently accumulated at the tumor site and achieved optimal tumor killing in the mouse breast cancer model. Changing Nanoparticle Components Tests Alternate Anti-cancer Strategies In the work published in Applied Materials & Interfaces, Chen and his colleagues describe the engineering of another nanoparticle that uses a different approach to the problem of MDR. This second nanoparticle is similar to the first in that it contains the centrally encapsulated doxorubicin surrounded by an outer hydrophilic surface layer that allows efficient transport through the bloodstream. However, this particle uses the gas nitric oxide (NO), which is known to block the system that pumps doxorubicin out of the cell. In addition, the NO is released from a compound called BNN6, which is activated by ultraviolet (UV) light. Thus, this nanoparticle is designed to be administered in the bloodstream and then activated with UV light when it reaches its cancer target. In experiments in cell culture, when hit with UV light the nanoparticles burst -- releasing the cell-killing doxorubicin and causing BNN6 to release the NO gas. The combination successfully inhibited the MDR machinery, resulting in chemosensitization and efficient cancer-cell killing. Based on the successful testing of this nanoparticle in cultured cells, the group expects it to perform well when tested in experiments in mice. Smart Nanomedicines vs Multidrug Resistance Chemotherapy is the most common treatment for cancer. Unfortunately, these drugs often cause minimal damage to tumors, because of MDR, and this can result in the expansion of populations of MDR tumors. Also, most chemotherapy drugs have very narrow therapeutic windows, frequently showing toxicity to healthy tissues and organs even at doses lower than required for a therapeutic effect. Therefore, there is an urgent need to devise ways to achieve high doses in tumor cells while eliminating harm to healthy tissue. Chen concludes, “The mechanism of MDR is interesting scientifically, but also incredibly important medically. That is why we are using our bioengineering skills to develop strategies to optimize the effect of these drugs on the cancer while reducing the toxicity to the surrounding tissues, which is both a major impediment to successful treatment as well as extremely taxing for cancer patients.” The work was funded by support from the Intramural Research Program, NIBIB. Funding from China was provided by The National Key Program for Developing Basic Research, the National Science Foundation, the Shenzhen Basic Research Program, the China Scholarship Council, and the Instrumental Analysis Center of Shanghai Jiao Ton University. Additional funds were provided by the European Union.
News Article | January 7, 2016
« Audi of America passed 200,000 unit mark in 2015 for annual sales for first time; 6th straight record year | Main | US Navy issues solicitation to lease 400-600 electric vehicles » Established automotive industry companies—not Silicon Valley—are leading the development of autonomous driving technology, according to a new report from the Intellectual Property and Science business of Thomson Reuters. The report, which analyzes global patent activity in the field of self-driving automobiles over the last five years, identifies the global leaders in the development of the technologies and also makes predictions about the future of driverless cars. According to the report—2016 State of Self-Driving Automotive Innovation—there were more than 22,000 new inventions related to self-driving automobiles between January 2010 and October 2015, with some clear leaders already emerging in the space. The analysts looked at three main categories of technology: autonomous driving, driver assistance and telematics. Autonomous driving was the clear leader in terms of innovation activity, while projections through year end show driver assistance potentially plateauing and telematics on the rise. … headlines over the past year have touted tech companies innovating in the automotive space. This isn’t a huge surprise, as current-day cars are more like giant computers on wheels than the transportation chariots they once replaced. As such, tech businesses dabbling in the automotive sector continue to attract attention … With all this publicity, it’s easy to surmise that tech companies are taking the lead in terms of automotive innovation. However, the truth is that the techies are far from leading the self-driving pack. To the contrary, automotive bellwethers are the ones in the driver’s seat. Toyota (Japan) is the overall global leader in autonomous automotive innovation, followed by Bosch (Germany), Denso (Japan), Hyundai (South Korea) and GM (US). The pool of potential candidates was evaluated against the three areas comprising self-driving car innovation: autonomous driving, driver assistance and telematics. Japan holds the world's leadership position in autonomous driving innovation (in conjunction with the field of collision avoidance) with four of the top five innovator spots: Toyota (Japan) leads the pack, followed by Denso (Japan), Bosch (Germany), Nissan (Japan) and Honda (Japan). Google ranks 19th in the world in this area, followed by Ford at number 20. Overall, Asia has 11 of the world’s top 20 autonomous-driving innovators according to the report. The Thomson Reuters analysts found that there are a number of other organizations innovating in this area, including some potential surprises such as Amazon (with 14 unique inventions); Boeing (35); IBM (34); Microsoft (10); Qualcomm (24); Samsung (107); and Southeast University in China (24). Carnegie Mellon University and MIT have four and seven unique inventions, respectively. In driver assistance technologies, Germany takes three of the top five innovator spots: Bosch leads the group while Daimler and Continental come in fourth and fifth, respectively. Toyota and Hyundai take the second and third places. GM is the top innovator in Telematics, followed by Hyundai, Marvell (US), LG and Denso. Although auto industry companies dominate the category, a number of more specialized technology and research institutions have amassed a noteworthy collection of self-driving vehicle-related patents. Among them, LG, Samsung, Google, Boeing, IBM, Amazon, Carnegie Mellon and MIT have all contributed significant new intellectual property in the category over the last five years. Given that, the field is ripe for partnership, according tomthe analysts. Thomson Reuters IP & Science analysts predict that Apple will make a collaboration announcement with Tesla in mid-January after CES; although Apple is not a leading innovator in this field—with only one invention overall in the area of self-driving vehicles—a partnership with Tesla would be a predictable move for both companies, based on a thorough review of both companies’ patent portfolios.
News Article | December 4, 2015
Rice University researchers who pioneered the development of laser-induced graphene have configured their discovery into flexible, solid-state microsupercapacitors that rival the best available for energy storage and delivery. The devices developed in the lab of Rice chemist James Tour are geared toward electronics and apparel. They are the subject of a new paper in the journal Advanced Materials. Microsupercapacitors are not batteries, but inch closer to them as the technology improves. Traditional capacitors store energy and release it quickly (as in a camera flash), unlike common lithium-ion batteries that take a long time to charge and release their energy as needed. Rice’s microsupercapacitors charge 50 times faster than batteries, discharge more slowly than traditional capacitors, and match commercial supercapacitors for both the amount of energy stored and power delivered. The devices are manufactured by burning electrode patterns with a commercial laser into plastic sheets in room-temperature air, eliminating the complex fabrication conditions that have limited the widespread application of microsupercapacitors. The researchers see a path toward cost-effective, roll-to-roll manufacturing. “It’s a pain in the neck to build microsupercapacitors now,” Tour says. “They require a lot of lithographic steps. But these we can make in minutes: We burn the patterns, add electrolyte and cover them.” Their capacitance of 934 microfarads per square centimeter and energy density of 3.2 milliwatts per cubic centimeter rival commercial lithium thin-film batteries, with a power density two orders of magnitude higher than batteries, the researchers claimed. The devices displayed long life and mechanical stability when repeatedly bent 10,000 times. Their energy density is due to the nature of laser-induced graphene (LIG). Tour and his group discovered last year that heating a commercial polyimide plastic sheet with a laser burned everything but the carbon from the top layer, leaving a form of graphene. But rather than a flat sheet of hexagonal rings of atoms, the laser left a spongy array of graphene flakes attached to the polyimide, with high surface area. The researchers treated their LIG patterns — interdigitated like folded hands — with manganese dioxide, ferric oxyhydroxide or polyaniline through electrodeposition and turned the resulting composites into positive and negative electrodes. The composites could then be formed into solid-state microsupercapacitors with no need for current collectors, binders or separators. Tour is convinced the day is coming when supercapacitors replace batteries entirely, as energy storage systems will charge in minutes rather than hours. “We’re not quite there yet, but we’re getting closer all the time,” he says. “In the interim, they’re able to supplement batteries with high power. What we have now is as good as some commercial supercapacitors. And they’re just plastic.” Rice graduate students Lei Li and Jibo Zhang and alumnus Zhiwei Peng are lead authors of the paper. Co-authors are Rice postdoctoral researchers Yongsung Ji, Nam Dong Kim, Gedeng Ruan, and Yang Yang and graduate students Yilun Li, Ruquan Ye, and Huilong Fei; Caitian Gao, a visiting graduate student at Rice from Lanzhou University, China; and Qifeng Zhong, a visiting graduate student at Rice from Southeast University, Nanjing, China. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of materials science and nanoengineering and of computer science. The Air Force Office of Scientific Research and its Multidisciplinary University Research Initiative and the Chinese Scholarship Council supported the research.
News Article | December 3, 2015
Home > Press > Scientists see the light on microsupercapacitors: Rice University's laser-induced graphene makes simple, powerful energy storage possible Abstract: ice University researchers who pioneered the development of laser-induced graphene have configured their discovery into flexible, solid-state microsupercapacitors that rival the best available for energy storage and delivery. The devices developed in the lab of Rice chemist James Tour are geared toward electronics and apparel. They are the subject of a new paper in the journal Advanced Materials. Microsupercapacitors are not batteries, but inch closer to them as the technology improves. Traditional capacitors store energy and release it quickly (as in a camera flash), unlike common lithium-ion batteries that take a long time to charge and release their energy as needed. Rice's microsupercapacitors charge 50 times faster than batteries, discharge more slowly than traditional capacitors and match commercial supercapacitors for both the amount of energy stored and power delivered. The devices are manufactured by burning electrode patterns with a commercial laser into plastic sheets in room-temperature air, eliminating the complex fabrication conditions that have limited the widespread application of microsupercapacitors. The researchers see a path toward cost-effective, roll-to-roll manufacturing. "It's a pain in the neck to build microsupercapacitors now," Tour said. "They require a lot of lithographic steps. But these we can make in minutes: We burn the patterns, add electrolyte and cover them." Their capacitance of 934 microfarads per square centimeter and energy density of 3.2 milliwatts per cubic centimeter rival commercial lithium thin-film batteries, with a power density two orders of magnitude higher than batteries, the researchers claimed. The devices displayed long life and mechanical stability when repeatedly bent 10,000 times. Their energy density is due to the nature of laser-induced graphene (LIG). Tour and his group discovered last year that heating a commercial polyimide plastic sheet with a laser burned everything but the carbon from the top layer, leaving a form of graphene. But rather than a flat sheet of hexagonal rings of atoms, the laser left a spongy array of graphene flakes attached to the polyimide, with high surface area. The researchers treated their LIG patterns -- interdigitated like folded hands -- with manganese dioxide, ferric oxyhydroxide or polyaniline through electrodeposition and turned the resulting composites into positive and negative electrodes. The composites could then be formed into solid-state microsupercapacitors with no need for current collectors, binders or separators. Tour is convinced the day is coming when supercapacitors replace batteries entirely, as energy storage systems will charge in minutes rather than hours. "We're not quite there yet, but we're getting closer all the time," he said. "In the interim, they're able to supplement batteries with high power. What we have now is as good as some commercial supercapacitors. And they're just plastic." Rice graduate students Lei Li and Jibo Zhang and alumnus Zhiwei Peng are lead authors of the paper. Co-authors are Rice postdoctoral researchers Yongsung Ji, Nam Dong Kim, Gedeng Ruan and Yang Yang and graduate students Yilun Li, Ruquan Ye and Huilong Fei; Caitian Gao, a visiting graduate student at Rice from Lanzhou University, China; and Qifeng Zhong, a visiting graduate student at Rice from Southeast University, Nanjing, China. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of materials science and nanoengineering and of computer science. The Air Force Office of Scientific Research and its Multidisciplinary University Research Initiative and the Chinese Scholarship Council supported the research. About Rice University Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nations top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,888 undergraduates and 2,610 graduate students, Rices undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for best quality of life and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplingers Personal Finance. Follow Rice News and Media Relations via Twitter @RiceUNews For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
News Article | March 21, 2016
Representation of measurements that demonstrate the contextuality-nonlocality tradeoff. Credit: Zhan, et al. ©2016 American Physical Society (Phys.org)—Two of the most important ideas that distinguish the quantum world from the classical one are nonlocality and contextuality. Previously, physicists have theoretically shown that both of these phenomena cannot simultaneously exist in a quantum system, as they are both just different manifestations of a more fundamental concept, the assumption of realism. Now in a new paper, physicists have for the first time experimentally confirmed that these two defining features of quantum mechanics never appear together. The physicists, Xiang Zhan, et al., have published a paper on the nonlocality-contextuality tradeoff in a recent issue of Physical Review Letters. In the everyday world that we observe, an object can only be affected by nearby objects (locality), and when we make a measurement, the outcome does not depend on other independent measurements being made at the same time (noncontextuality). In contrast, the quantum world is nonlocal, as demonstrated by quantum entanglement where two objects can influence each other even when separated by large distances. And in the quantum world, measurements are contextual, so quantum systems do not have predetermined values but instead their values depend on how measurements are made. To show that a quantum system is nonlocal or contextual, physicists have defined inequalities that assume a system is the opposite (local or noncontextual). Then they perform experiments that attempt to violate these inequalities to show that the system is not local or noncontextual. So far, these two types of inequalities have never been tested simultaneously. In the new study, the researchers have attempted to violate both inequalities at the same time, but have found that only one inequality can be violated at once. Their experiment uses entangled photons to generate photonic qutrit-qubit systems (a qubit is a superposition of two states, whereas a qutrit is a superposition of three states). By performing various measurements on these photons, the researchers could violate the inequalities separately, but not at the same time. "The greatest significance of our work is that we provide experimental evidence of the assumption that quantum entanglement and contextuality are intertwined quantum resources," Peng Xue, a physicist at Southeast University in Nanjing, China, and one of the lead authors of the paper, told Phys.org. As the physicists explain, the reason for the nonlocality-contextuality tradeoff arises from the fact that both properties have the same root: the assumption of realism, which is the assumption that the physical world exists independent of our observations, and that the act of observation does not change it. Since nonlocality and contextuality can be thought of as two different manifestations of the basic assumption of realism, then one of them can be transformed into the other, but both cannot exist at the same time because they are essentially the same thing. "We think the contextuality-nonlocality monogamy suggests the existence of a quantum resource of which entanglement is just a particular form," Xue said. "The resource required to violate the noncontextuality inequality and that required to violate the locality inequality are fungible through entanglement. That is, to violate the locality inequality costs entanglement as a resource, while to violate the noncontextuality inequality costs contextuality as a resource. In a quantum system, only one of the two inequalities can be violated because nothing is left to violate the other one." The researchers hope that the new experiment will open the doors to further exploring the mutual resource in the future, as well as lead to potential applications. "We plan to study contextuality as a resource for experimental quantum information processing, such as for quantum computation," Xue said. More information: Xiang Zhan, et al. "Realization of the Contextuality-Nonlocality Tradeoff with a Qubit-Qutrit Photon Pair." Physical Review Letters. DOI: 10.1103/PhysRevLett.116.090401
Southeast University | Date: 2011-03-02
A new three-dimensional measurement method based on wavelet transform to solve the phase distribution of a fringe pattern accurately and obtain three-dimensional profile information of a measured object from phase distribution. The method includes: projecting a monochrome sinusoidal fringe pattern onto the object; performing wavelet transform for the deformed fringe pattern acquired with CCD line by line, solving the relative phase distribution by detecting the wavelet ridge line, recording the wavelet transform scale factors at the line, and creating a quality map; dividing the relative phase distribution into two parts according to the map, and performing direct-phase unwrapping for the part with better reliability using a scan line based algorithm, and unwrapping the part with lower reliability using a flood algorithm under the guide of the quality map, to obtain the absolute phase distribution of the fringe pattern; obtaining the three dimensional information using a phase-height conversion.