Silicon Nanowire Based Platform Device for Chemical/Bio-Chemical Sensing Applications

TLDR: In this article, a low input referred noise frequency converter circuit is proposed to generate spikes with the help of Leaky integrate and fire neuron model (LIF) where firing delay maps to the strength of the stimulation across the array.

Abstract: Silicon nanowire (SiNW) arrays are fabricated using complementary metal-oxide semiconductor (CMOS) compatible technology, for the detection of proteins, pH levels, cardiac biomarker troponin-T (cTnT) etc. The sensor output is fed to a ‘current to frequency converter circuit’. Neuromorphic approach based low input referred noise frequency converter circuit is developed. The circuit generates a sequence of spikes with the help of Leaky integrate and fire neuron model (LIF) where firing delay maps to the strength of the stimulation across the array. The proposed read-out circuit is implemented using Tower Jazz Semiconductor's 0.18μm CMOS technology. The SiNW arrays are producing current change from 200pA to 1.6nA for a corresponding change of 50m V/0.5ng/ml protein concentration at the gate. The circuit is able to detect a change in current as low as 50pA and consuming IlμW power and 93×17μm2silicon area.