Double-meander spring silicon piezoresistive sensors as microforce calibration standards

Abstract

A transferable force calibration standard based on a silicon microelectromechanical sensor has been designed, fabricated, and characterized for micrometrology applications. Two essential elements of doublemeander springs and full piezoresistive etched p-silicon-on-insulator Wheatstone bridges (WBs) are integrated to the sensor for enhancing the device's sensitivity and eliminating the current leakage during an active sensing operation, respectively. The design process is supported by three-dimensional finite element modeling to select the optimal proposed sensors as well as simulating their mechanical and electrical properties in the desired force range (≤1000 μN). To fabricate the microforce sensors, a bulk micromachining technology is used by frequently involving an inductively coupled plasma deep reactive ion etching at cryogenic temperature. Several optical and electrical characterization techniques have been utilized to ensure the quality of the fabricated WBs, where their measured offset voltage can be down to 0.03 AE 0.071 mV∕V. In terms of its linearity, the fabricated device exhibits a small nonlinearity of <3%, which leads this sensor to be appropriate for precise microforce standard. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Novel resonant pressure sensor based on piezoresistive detection and symmetrical in-plane mode vibration

“…Piezoresistive resistors are widely used in MEMS piezoresistive sensors 20,21 , and in resonant pressure sensors, piezoresistor layouts are important for resonant pressure sensor signal detection quality, such as the adjacent mode signal shielding ability and vibration amplitude sensitivity. Based on the resonant mode simulation and static pressure simulation results, the coupling beam will not be deformed during first-order mode vibration; thus, placing the detection piezoresistors in the coupling beam to decrease noise from adjacent modes is reasonable.…”

Transferable micromachined piezoresistive force sensor with integrated double-meander-spring system

“…Meander-type springs in combination with bending springs are well suited to take up the lateral strain, which increases with the deflection of the probing body and are thus able to provide a large linear range of the micro force artifact. Samples of this artifact, which were realized using reactive ion etching (RIE) at cryogenic temperature in silicon, confirm the load-deflection behavior derived from finite element modeling (FEM; Hamdana et al, 2016;Wasisto et al, 2015a). For an application under industrial conditions the micro force artifact comprises a strain-sensing piezoresistive Wheatstone bridge (WB) of very low cross-sensitivity to non-constant ambient conditions such as temperature, humidity and light.…”

“…5b). However, this deviation was not crucial to the sensor performance in general (Hamdana et al, 2016). Moreover, this irregularity can be eliminated with fine tuning of the etch recipe, especially regarding the distribution of the process temperature.…”

Tailoring stresses in piezoresistive microcantilevers for enhanced surface stress sensing: insights from topology optimization

“…As a result, our current model predominantly operates in a 2D framework, rendering our findings less applicable to sensor designs incorporating intricate 3D features. 40,41) However, it is important to note that the underlying methodology of TO can be extended to 3D models, albeit at the cost of increased computational cost. The optimization objective is defined to be the sensitivity, that is, the resistance changes at the piezoresistor divided by unit surface stress :…”