A sensor is a device that measures a chemical or physical event and converts it into a signal which can be read by an observer or an instrument. Sensors are able to provide feedback on the world around us, similar to our own five senses of taste, sight, hearing, touch, and smell. Obtaining such information enables the possibility of understanding and controlling the processes and events of interest in more effective ways. Sensors applications include environmental and health monitoring, air and water quality assessment, industrial process monitoring, search & rescue operations, and security. The driving forces for continued interest and advancements in sensing technology include reducing cost, reducing size, improving sensitivity and selectivity and autonomous self-powering devices. Broadly, sensors can be divided to physical (e.g., temperature, pressure) and chemical (e.g., NOx, H2S) sensing devices.
Electrochemical Chem/Bio Sensing Based on Modified Graphene
The extraordinary electrical properties of graphene make it an excellent candidate for next generation electrochemical sensors for gas or liquid sensing. Our efforts are focused in the growth and modification of graphene sheets with metal nanoparticles (image at left) through electroless deposition that are transferred onto different transducers (e.g., screen printed electrodes and interdigitated electrodes) depending on the final desired applications. Further modification of the metal nanoparticle with biomarkers and biomolecules for more specific recognition is also of interest.
Research contacts: Anna
Silicon Carbide Sensors for Harsh Environment Conditions
Creation of low cost reliable, zero emission power plants require advanced sensors and controls for operation and achievement of performance goals. MEMS based sensors are attractive for these applications because they are small and inexpensive, yet they can provide real-time information. High temperatures, high pressures or corrosive environments are common industrial conditions. In order to survive under in these conditions, we are developing new sensors based on more stable materials, such as silicon carbide. The main applications for these sensors are continuous, real-time, in situ detection, identification, and measurement of combustion gases such as H2, COx, NOx, and H2S. The research includes development of effective sensing materials and novel sensor designs.
Research contacts: Carlo, Lunet
Microheater-Based Platform for Combustible Gas Sensing
The widespread use of chemical sensors can give access to new streams of information to both industries and consumers. However, many existing chemical sensors, especially ones that require heated sensing materials, are bulky or have a large power consumption that prevent the use of portable power sources like batteries. The goal of this project is to develop small, low power chemical sensors with competitive performance and reliability. The sensors are based upon a microheater platform we have developed that requires ~10 mW to reach 350 °C. We have successfully sensed hydrogen using a novel catalyst material of Pt nanoparticles-functionalized graphene aerogels and Pt nanoparticle-functionalized boron-nitride aerogels. Long-range goals include the development of novel catalyst materials for sensing, improved catalyst integration with the microheater platform, and investigation of materials issues for long-term reliability.
M. Vincent, J. Zhang, Carlo Carraro, R. Maboudian, “A SiC Metallization Scheme using an ALD Protective Layer for Harsh Environment Devices”, Proceedings of IEEE MEMS Conference, pp. 385-388, (2012).
A. Gutés, B. Hsia, A. Sussman, W. Mickelson, A. Zettl, C. Carraro, R. Maboudian, "Graphene decoration with metal nanoparticles: Towards easy integration for sensing applications", Nanoscale, 4, 438-440 (2012).
A. Gutés, C. Carraro, R. Maboudian, "Nonenzymatic Glucose Sensing Based on Deposited Palladium Nanoparticles on Epoxy-Silver Electrodes", Electrochimica Acta, 56, 5855-5859 (2011).
A. Gutés, I. Laboriante, C. Carraro, R. Maboudian, "Palladium Nanostructures from Galvanic Displacement as Hydrogen Peroxide Sensor", Sensors and Actuator-B, 147, 681 (2009).
A. Gutés, I. Laboriante, C. Carraro, R. Maboudian, "Silver Nanostructures on Silicon Based on Galvanic Displacement Process", J. Phys. Chem. C, 113, 16939–16944 (2009).
M. Cerruti, J. Jaworski, J. Varadarajan, C. Carraro, S.-W. Lee, A. Majumdar, R. Maboudian, “Polymer-oligopeptide Composite Coating for Selective Detection of Explosives”, Analytical Chemistry, 81, 4192-4199 (2009).