Organic nano-electro-mechanical-sensor systems for healthcare and environmental applications

Abstract

Organic field effect transistors and polymer microcantilevers are two classes of organic sensors with potential applications in biochemical sensing. The organic field effect transistors (OFETs) with region regular poly3-hexylthiophene(rr-P3HT) and hexafluoro-2-propanol-substituted polysiloxane (SXFA) as an organic layer, have been used for detection of explosive vapors with excellent sensitivity of less than 70 ppt for 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and less than 100 ppt for 2,4,6-trinitrotoluene (TNT) [1–3]. Piezo-resistive & piezo-electric polymer composite microcantilevers have been demonstrated as sensitive and cost effective platforms for bio-chemical detection [4–12]. Integration of the OFET and the polymer cantilever platform can bring orthogonality to the sensing where selectivity is a critical requirement. We have recently achieved this by integrating a strain sensitive organic field effect transistor (OFET) on the surface of a polymer nanomechanical cantilever [6]. This sensor named as the “Organic CantiFET” shows the highest deflection and surface stress sensitivity reported till date and opens up opportunities for realizing highly sensitive yet selective low cost polymer sensors for a variety of applications.