Ultrasensitive sensor design based on controlled crack formation

Abstract

In this thesis, we describe crack sensor systems inspired by spiders slit organ. Firstly, we present a sensor based on the guided formation of straight mechanical cracks within a regular micro-scale pattern. The sensor is highly sensitive to pressure (sensitivity = ~ 1 × 105 at pressures of 8-9.5 kPa range) as well as strain (GF = ~ 2 × 106 at strains of 0-10% range). Secondly, we present crack sensor based on a cracked transparent epilayer, Indium-Tin Oxide (ITO), deposited on a transparent PET substrate, which exhibits ultra-high sensitivity to strain, (GF = ~ 4000 at 2% strain), to pressure (sensitivity = 1.91 kPa-1 at pressure from 30 to 70 kPa), and transparency (89% at wavelength of 560 nm). Theoretical description, durability and reproducibility have also been demonstrated for each case.