Microelectromechanical (MEM) devices are useful in a large variety of applications including RF Electronics and Sensors. III-Nitride semiconductors are highly promising for MEMS based sensors due to their unique spontaneous and piezoelectric polarization and chemical inertness, which can result in highly sensitive strain/deflection transduction and harsh environment operation. Our major sub-focus areas within this major focus area are listed below:

(i) Handheld sensor systems using III-Nitride piezotransistive microcantilevers:

MEMS sensors that can electronically transduce strain/deflection are highly desirable for designing integrated and array based sensor systems that consume very low power. NESL has pioneered the development of GaN based MEM sensors using ultra-sensitive “piezotransistor” or strain sensitive AlGaN/GaN HFET fabricated at the high strain region of the MEMS devices. Due to very strong polarization properties of III-Nitride MEMS they can be used to transduce ultra-small deflections down to femtoscale regime. A major research focus of our group is to exploit this extreme sensitivity and develop handheld systems for various sensing applications, including detection of nuclear and infrared radiation, and analyte molecules through photoacoustic spectroscopy.

(ii)  III-Nitride microcantilever heater based miniaturized sensor systems:

Taking advantage of the polarization properties of III-Nitrides and their chemically inert nature, we have designed and fabricated novel III-Nitride based microcantilever heaters and their arrays that are capable of highly sensitive and selective detection of various analytes including volatile organic compounds. We have demonstrated, for the first time, miniaturized III-Nitride heater filament based selective detection of analytes, and our group is engaged in utilizing these microscale heaters to develop miniaturized sensor systems offering high sensitivity and selectivity as well as low power consumption.