Testing of a single-polarity piezoresistive three-dimensional stress-sensing chip

Abstract

A new piezoresistive stress-sensing rosette is developed to extract the components of the three-dimensional (3D) stress tensor using single-polarity (n-type) piezoresistors. This paper presents the testing of a micro-fabricated sensing chip utilizing the developed single-polarity rosette. The testing is conducted using a four-point bending of a chip-on-beam to induce five controlled stress components, which are analyzed both numerically and experimentally. Numerical analysis using finite element analysis is conducted to study the levels of the induced stress components at three rosette-sites and the levels of the stress field non-uniformities, and to simulate the extracted stress components from the sensing rosette. The experimental analysis applied tensile and compressive loads over three rosette-sites at different load increments. The experimentally extracted stress components show good linearity with the applied load and values close to the numerical model.

Development of MEMS-based piezoresistive 3D stress/strain sensor using strain technology and smart temperature compensation

“…The 4PB loading is a well-known test of uniaxial stress, however a significant amount of out-of-plane shear stress accumulates at the chip boundaries due to the bending load. Thus, the prior state-of-art of 3D stress sensors utilized the 4PB test to validate those chip capability of measuring the out-of-plane shear stress [13]. Herein, the same loading setup was employed to apply dynamic out-of-plane shear stress at different temperatures.…”

“…They were able to construct a sensing rosette, consists of two groups of p and n-type piezoresistors oriented over (111) silicon substrate, which is capable of monitoring the 3D stress/strain state. Gharib et al were able to devise a single-polarity (n-type) PR sensor for thermally compensated 3D stress measurement [11][12][13]. The use of only n-type piezoresistors, to develop 3D stress/strain rosettes, is found to be more appealing due to the simplicity of the microfabrication since there is no need for the p-type doping equipment.…”

6-Axis Stress Tensor Sensor Using Multifaceted Silicon Piezoresistors

“…To reduce the size of the sensor chip, sensors which use piezoresistors [ 9 , 10 ] and complementary metal-oxide semiconductor(CMOS)-based structures [ 11 , 12 ] were reported. Wailed A Moussa et al, reported a multi-axes stress tensor sensor which can detect five-directional components of the stress tensor by placing piezoresistive elements in multiple positions [ 9 ]. They also succeed to prevent the effect of temperature change by comparing the responses of several piezoresistors [ 10 ].…”