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Miami, FL, United States

Gaitas A.,PICOCAL, Inc. | Gaitas A.,Technical University of Delft | French P.,Technical University of Delft
Sensors and Actuators, A: Physical | Year: 2012

Microcantilevers are used in a number of applications including atomic-force microscopy (AFM). In this work, deflection-sensing elements along with heating elements are integrated onto micromachined cantilever arrays to increase sensitivity, and reduce complexity and cost. An array of probes with 5-10 nm gold ultrathin film sensors on silicon substrates for high throughput scanning probe microscopy is developed. The deflection sensitivity is 0.2 ppm/nm. Plots of the change in resistance of the sensing element with displacement are used to calibrate the probes and determine probe contact with the substrate. Topographical scans demonstrate high throughput and nanometer resolution. The heating elements are calibrated and the thermal coefficient of resistance (TCR) is 655 ppm/K. The melting temperature of a material is measured by locally heating the material with the heating element of the cantilever while monitoring the bending with the deflection sensing element. The melting point value measured with this method is in close agreement with the reported value in literature. © 2011 Elsevier B.V. All rights reserved. Source

Agency: National Science Foundation | Branch: | Program: STTR | Phase: Phase I | Award Amount: 149.87K | Year: 2010

This Small Business Technology Transfer Phase I project aims to develop highly sensitive and inexpensive uncooled microbolometers using ultra-thin films of metals, metal oxides, or semi-metals. These microbolometers will be attractive for use in portable night vision devices and other thermal imaging applications that require a Noise Equivalent Temperature Difference (NETD) of less than 20 mK. We have already demonstrated metal microbolometers microfabricated from titanium thin films on SiO2/Si3N4/SiO2 cantilevers with a negative temperature coefficient of resistance (TCR) as high as - 0.67%/K (which is higher than that of bulk titanium films), with a NETD of approximately 18 mK and a 1/f noise lower than that of vanadium oxide films. The TCR can be further increased to values greater than 2%/K using alternative metals, metal oxides, or semimetals. Furthermore, thin film metallic or semimetallic microbolometers have low noise characteristics and other important advantages, including a simplified fabrication process and a lower manufacturing cost. The broader impact/commercial potential of this project is to achieve low-cost and high-sensitivity infrared (IR) detection with uncooled microbolometers, which will allow the replacement of cooled IR detectors in some low-end military and civilian applications, including night vision, navigation, biological radiometry, target discrimination, spectroscopy, and thermal profiling. Microbolometers can be further scaled down to reduce each pixel?s thermal mass, allowing a faster response to a given amount of radiation, while maintaining or improving mechanical strength. By exploring other ultra-thin film materials for uncooled IR detectors, the manufacturing cost, reliability, and uniformity can be further improved during the fabrication process. This research work will also help us further understand the electrical, optical, mechanical and thermal properties of ultrathin films of metals and semimetals. The proposed activity broadens the participation of underrepresented groups, since senior research scientists involved belong to underrepresented groups. Undergraduate involvement in this project will enhance NSF?s educational goals. Finally, the results of this project will be disseminated through publications in scientific and industry journals.

Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 499.69K | Year: 2008

This Small Business Innovation Research (SBIR) Phase II project aims to produce a commercial prototype of a state-of-the-art high throughput scanning probe microscope (HT-SPM), which can be used for measuring topography and thermal parameters in nanotechnology, bio, and semiconductor applications. The scanning probe microscope has been a very successful tool, but emphasis has not been put on rapid data acquisition. The HT-SPM is an enabling technology that consists of a transformative and patented method for extracting topography which allows for higher throughput. The project leverages experience in atomic force microscope (AFM) probe micro-fabrication and industry. An immediate outcome of this SBIR project will be a fully functional and market ready HT-SPM. The broader impact/commercial potential of measurements in nanometer scale devices and structures have both scientific and industrial importance. Although the Atomic Force Microscope (AFM) is one of the most important tools for nanotechnology, there has not been any fundamental innovation in the way it operates for more than a decade. This project provides faster measurement as a result of a fundamentally different way of imaging. Faster characterization permits manufacturers to expedite problem isolation, leading to higher productivity and higher return-on-investment (ROI). The HT-SPM also benefits R&D, failure analysis and off-line engineering. The HT-SPM offers critical capabilities that will allow users too quickly and clearly measure topography/friction/temperature at the nanoscale and view critical characteristics. The HT-SPM fills a critical need in integrated circuits, nanotechnology, life sciences and other markets that rely on sub-micron microscopy, as it will provide users with a superior and inexpensive measurement system to aid in studying new properties.

Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2007

The Small Business Innovation Research (SBIR) Phase I project will develop a high throughput scanning probe microscopy system for measuring topography and thermal parameters in nanotechnology, bio and semiconductor applications. The need for higher throughput in scanning probe microscopy will be addressed using ultracompliant probe arrays in which multiple tips scan in parallel; thus, making it possible for many of these arrays to operate simultaneoulsy on a sample with minimal contact force and without mechanical feedback. The proposed technology will fill a critical need in markets that rely on sub-micron microscopy. The proposed system will provide faster measurements, thereby contributing to higher productivity and cost reduction. In addition, it will benefit R&D, failure analysis and off-line engineering.

Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.78K | Year: 2009

This Small Business Innovation Research Phase I research project develops an inexpensive, rugged piezo-resistive micro-cantilever sensor array for explosives and toxins detection with the ability for wireless data transmission. The sensor can identify analytes by changes in the electronic properties of the sensor material due to analyte absorption or binding. The sensitivities and detection limits are significantly improved by using ultra-compliant coated polymers that show a high degree of sensitivity and selectivity to different explosives. Ultrathin metallic piezo-resistive sensors are embedded into the cantilevers to enable both static and dynamic measurements. Compared to micro gas chromatographic systems and film based sensor arrays for detection of explosives, the sensor proposed has several advantages including a low-cost fabrication process, higher sensitivity for lower detection limits, and highly selective coating materials for absorption of chemical vapors from Improvised Explosive Devices (IED). Remote detection systems for explosives are of great concern for homeland security. This proposed sensor can potentially enable low-cost and reliable handheld systems for remote explosive detection or help develop wireless explosive sensing networks for cargos, buildings and other security needs. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

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