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Chiadini F.,University of Salerno | Fiumara V.,University of Basilicata | Scaglione A.,University of Salerno | Pulsifer D.P.,Pennsylvania State University | And 4 more authors.
Optics and Photonics News | Year: 2011

Researchers are looking to the compound eyes of insects as a model for developing their unique approach to harvesting sunlight. Each compound eye comprises several cylindrical eyelets called ommatidia that are arrayed on a curved surface. Light propagating along the axis of an ommatidium is collected to form an image, but light propagating in other directions and reaching an ommatidium is absorbed by its dark side wall. The first phase requires the numerical simulation of light interacting with the air-silicon interface. A simplified two-dimensional bioinspired texturing of the exposed face was considered as the first step of this phase. Results indicated that the bioinspired textured solar cell exhibits light-coupling efficiency. A Nano4 technique has been developed to manufacture multiple high-fidelity replicas of a single biotemplate. The technique can produce multiple replicas simultaneously of multiple biotemplates.

Guo J.,Materials Research Institute, LLC | Wang W.,Materials Research Institute, LLC | Wang W.,Zhejiang Wanli University | Hu J.,Materials Research Institute, LLC | And 8 more authors.
Biomaterials | Year: 2016

Bacterial and fungal infections in the use of surgical devices and medical implants remain a major concern. Traditional bioadhesives fail to incorporate anti-microbial properties, necessitating additional anti-microbial drug injection. Herein, by the introduction of the clinically used and inexpensive anti-fungal agent, 10-undecylenic acid (UA), into our recently developed injectable citrate-based mussel-inspired bioadhesives (iCMBAs), a new family of anti-bacterial and anti-fungal iCMBAs (AbAf iCs) was developed. AbAf iCs not only showed strong wet tissue adhesion strength, but also exhibited excellent in vitro cyto-compatibility, fast degradation, and strong initial and considerable long-term anti-bacterial and anti-fungal ability. For the first time, the biocompatibility and anti-microbial ability of sodium metaperiodate (PI), an oxidant used as a cross-linking initiator in the AbAf iCs system, was also thoroughly investigated. Our results suggest that the PI-based bioadhesives showed better anti-microbial properties compared to the unstable silver-based bioadhesive materials. In conclusion, AbAf iCs family can serve as excellent anti-bacterial and anti-fungal bioadhesive candidates for tissue/wound closure, wound dressing, and bone regeneration, especially when bacterial or fungal infections are a major concern. © 2016 Elsevier Ltd.

Sun K.G.,Materials Research Institute, LLC | Sun K.G.,Pennsylvania State University | Nelson S.F.,Eastman Kodak Co. | Jackson T.N.,Materials Research Institute, LLC | Jackson T.N.,Pennsylvania State University
Device Research Conference - Conference Digest, DRC | Year: 2015

Vertical thin film transistors (VTFTs) achieve sub-micron channel length without expensive high-resolution photolithography by taking advantage of a three-dimensional device structure. Recently, ZnO VTFTs with active layers deposited by spatial atomic layer deposition (SALD) were demonstrated with large current density (10 mA/mm), high mobility (>14 cm2/Vs) and large on-off ratio (>107) [1]. Asymmetric saturation-region current-voltage characteristics were also obtained when the transistor source and drain electrodes were interchanged. Using the Synopsys Sentaurus drift-diffusion simulator we developed a physics-based two-dimensional model for SALD ZnO VTFTs. Using the model, we are able to reproduce the electrical behavior of the ZnO VTFTs and understand the role of nanometer-scale features in the device structure. © 2015 IEEE.

Zhang Y.,University of Texas at Arlington | Tran R.T.,Materials Research Institute, LLC | Qattan I.S.,University of Texas at Arlington | Tsai Y.-T.,University of Texas at Arlington | And 3 more authors.
Biomaterials | Year: 2013

The field of tissue engineering and drug delivery calls for new measurement tools, non-invasive real-time assays, and design methods for the next wave of innovations. Based on our recent progress in developing intrinsically biodegradable photoluminescent polymers (BPLPs) without conjugating organic dyes or quantum dots, in this paper, we developed a new type urethane-doped biodegradable photoluminescent polymers (UBPLPs) that could potentially serve as a new tool to respond the above call for innovations. Inherited from BPLPs, UBPLPs demonstrated strong inherent photoluminescence and excellent cytocompatibility in vitro. Crosslinked UBPLPs (CUBPLPs) showed soft, elastic, but strong mechanical properties with a tensile strength as high as 49.41 ± 6.17 MPa and a corresponding elongation at break of 334.87 ± 26.31%. Porous triphasic CUBPLP vascular scaffolds showed a burst pressure of 769.33 ± 70.88 mmHg and a suture retention strength of 1.79 ± 0.11 N. Stable but photoluminescent nanoparticles with average size of 103 nm were also obtained by nanoprecipitation. High loading efficiency (91.84%) and sustained release of 5-fluorouracil (up to 120 h) were achieved from UBPLP nanoparticles. With a quantum yield as high as 38.65%, both triphasic scaffold and nanoparticle solutions could be non-invasively detected in vivo. UBPLPs represent an innovation in fluorescent biomaterial design and may offer great potential in advancing the field of tissue engineering and drug delivery where bioimaging has gained increasing interest. © 2013 Elsevier Ltd.

Mor G.K.,Materials Research Institute, LLC | Basham J.,Materials Research Institute, LLC | Paulose M.,Materials Research Institute, LLC | Kim S.,Pennsylvania State University | And 4 more authors.
Nano Letters | Year: 2010

Solid-state dye-sensitized solar cells (SS-DSCs) offer the potential to make low cost solar power a reality, however their photoconversion efficiency must first be increased. The dyes used are commonly narrow band with high absorption coefficients, while conventional photovoltaic operation requires proper band edge alignment significantly limiting the dyes and charge transporting materials that can be used in combination. We demonstrate a significant enhancement in the light harvesting and photocurrent generation of SS-DSCs due to Förster resonance energy transfer (FRET). TiO2 nanotube array films are sensitized with red/near IR absorbing SQ-1 acceptor dye, subsequently intercalated with Spiro-OMeTAD blended with a visible light absorbing DCM-pyran donor dye. The calculated Förster radius is 6.1 nm. The donor molecules contribute a FRET-based maximum IPCE of 25% with a corresponding excitation transfer efficiency of approximately 67.5%. © 2010 American Chemical Society.

Li Y.V.,Materials Research Institute, LLC | Li Y.V.,Pennsylvania State University | Ramirez J.I.,Materials Research Institute, LLC | Ramirez J.I.,Pennsylvania State University | And 4 more authors.
Device Research Conference - Conference Digest, DRC | Year: 2012

We report here double-gate ZnO thin film transistor (TFT) circuits with operation at low voltage. TFTs with low voltage operation have been reported previously, but often use very thin (few nm thick) gate dielectric which may limit manufacturability [1]. Oxide semiconductor-based TFTs have been extensively studied as competitive candidates for next-generation display technology and other large-area electronics. For many applications, operation at voltages compatible with low-voltage CMOS is important. Double-gate TFTs are of interest because they allow threshold voltage tuning, improved device performance, and circuit applications like mixers. [2,3] We have previously reported bottom-gate ZnO TFTs and circuits fabricated on glass and flexible polymeric substrates using plasma enhanced atomic layer deposition (PEALD) [4,5]. Here we report double-gate ZnO TFTs and circuits fabricated on glass substrates using PEALD with a maximum process temperature of 200 °C. Compared to bottom-gate ZnO TFTs, double-gate ZnO TFTs have higher mobility, and reduced substhreshold slope. In these devices, the top gate can be used to vary the bottom-gate threshold voltage by more than 4 V. This allows the logic transition point for circuits to be adjusted as desired and allows logic operation at low voltage. 15 stage double-gate ZnO TFT ring oscillators operate well with V DD = 1.2 V, I D = 32 μA, and propagation delay of 2.1 μs/stage. © 2012 IEEE.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.98K | Year: 2013

ABSTRACT: This SBIR Phase I program is to develop and transition a lightweight shielding material technology for wideband electromagnetic shielding and high power microwave hardening of aircraft signal and power cables. Materials Research Institute proposes to use metalized nanometric and micrometric materials as conductive fillers to formulate the lightweight shielding material. Model simulation will be employed to identify and verify the most promising conductive filler and optimize the structure and composition of the shielding material. Prototype shielding materials will be fabricated for shielding effectiveness characterization. Experimental data and simulation results will be reviewed to refine the shielding material with a goal leading to a successful demonstration of the material concept feasibility on 6-ft long shielded cables. BENEFIT: The proposed lightweight shielding material is expected to have advantages over cable shields made of metal wires or metal particulates in weight savings, flexibility, mechanical durability, higher shielding capability, and lower manufacturing cost. It is also expected to have advantages over shielding materials made of carbon nanotubes or carbon nanofibers in lower cost, greater mechanical durability, and higher shielding performance.

PubMed | Materials Research Institute, LLC
Type: Journal Article | Journal: Materials letters | Year: 2010

Most natural waters are probably ultra dilute: aquasols. While the composition of such waters is routinely characterized thoroughly with respect to composition, very little attention has been paid to the solid phases which are certainly suspended in most, if not all, such. Our recent work having established the importance of the structure of water on its properties, [[1]; R. Roy, W.A. Tiller, I. Bell, M.R. Hoover; Mater Res Innov. 9 (2005) 577.] we have examined the structures of many waters with easily demonstrated (e.g. silver aquasols) or long-claimed (e.g. homeopathic remedies) biological effects. The results show that such materials can be easily distinguished from the pure solvent, and from each other, by the use of UV-VIS and Raman spectroscopy, while FTIR is insensitive to these differences. This opens up a whole new field of endeavor for inorganic materials scientists interested in biological effects.

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