Piezotransistive transduction of femtoscale displacement for photoacoustic spectroscopy.

ABSTRACT: Measurement of femtoscale displacements in the ultrasonic frequency range is attractive for advanced material characterization and sensing, yet major challenges remain in their reliable transduction using non-optical modalities, which can dramatically reduce the size and complexity of the transducer assembly. Here we demonstrate femtoscale displacement transduction using an AlGaN/GaN heterojunction field effect transistor-integrated GaN microcantilever that utilizes piezoelectric polarization-induced changes in two-dimensional electron gas to transduce displacement with very high sensitivity. The piezotransistor demonstrated an ultra-high gauge factor of 8,700 while consuming an extremely low power of 1.36?nW, and transduced external excitation with a superior noise-limited resolution of 12.43?fm?Hz(-1/2) and an outstanding responsivity of 170?nV?fm(-1), which is comparable to the optical transduction limits. These extraordinary characteristics, which enabled unique detection of nanogram quantity of analytes using photoacoustic spectroscopy, can be readily exploited in realizing a multitude of novel sensing paradigms.

SUBMITTER: Talukdar A 

PROVIDER: S-EPMC4918345 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature