Nano strain-amplifier: making ultra-sensitive piezoresistance in nanowires possible without the need of quantum and surface charge effects

TL;DR

This paper introduces a nano strain-amplifier design that significantly boosts the sensitivity of piezoresistive nanowire sensors without relying on quantum or surface charge effects, enabling ultra-sensitive mechanical detection.

Contribution

The paper proposes a novel nano strain-amplifier structure inspired by dogbone design, enhancing nanowire strain sensitivity without quantum or surface charge effects.

Findings

Enhanced sensitivity by at least 5.4 times compared to conventional structures

Demonstrated in p-type cubic silicon carbide nanowires

Potential for ultra-sensitive mechanical sensing applications

Abstract

This paper presents an innovative nano strain-amplifier employed to significantly enhance the sensitivity of piezoresistive strain sensors. Inspired from the dogbone structure, the nano strain-amplifier consists of a nano thin frame released from the substrate, where nanowires were formed at the centre of the frame. Analytical and numerical results indicated that a nano strain-amplifier significantly increases the strain induced into a free standing nanowire, resulting in a large change in their electrical conductance. The proposed structure was demonstrated in p-type cubic silicon carbide nanowires fabricated using a top down process. The experimental data showed that the nano strain-amplifier can enhance the sensitivity of SiC strain sensors at least 5.4 times larger than that of the conventional structures. This result indicates the potential of the proposed strain-amplifier for ultra-sensitive mechanical sensing applications.