Analysis of piezoresistive silicon as sense element for use in flexible tactile sensors

This paper presents the bending analysis of stresssensor chips of 300 µm and 100 µm thickness. Previous work on similar topics is usually heavily focused on ultra-thin chips (≤20 µm) and their reliability analysis for flexible applications. However, this paper aims to prove that flexible tactile sensors can be made using silicon resistors as the primary stress elements and can demonstrate good results even at intermediate thickness levels. The silicon resistors show a linear temperature response and can be oriented to have directional stress sensitivity, proving superior to other organic sensors. The motivation behind this research is to make the tactile sensor solely using CMOS circuits and, therefore, integrate both the sensor and the readout circuitry in one chip. This is extremely useful if the tactile sensors are used on a large scale and must be fabricated commercially using existing infrastructure.