Detailed Study of Amplitude Nonlinearity in Piezoresistive Force Sensors

Sensors

Leonel Paredes-Madrid¹  Luis Emmi²  Elena Garcia² 

[1]Centre for Automation and Robotics, UPM-CSIC, Ctra. Campo Real Km 0.2, Madrid 28500, Spain

关键词: piezoresistive;    force;    sensor;    nonlinear;    model;    tanh;    piezocapacitive;    FlexiForce;   

DOI  :  10.3390/s110908836

来源: mdpi

【 摘 要 】

This article upgrades the RC linear model presented for piezoresistive force sensors. Amplitude nonlinearity is found in sensor conductance, and a characteristic equation is formulated for modeling its response under DC-driving voltages below 1 V. The feasibility of such equation is tested on four FlexiForce model A201-100 piezoresistive sensors by varying the sourcing voltage and the applied forces. Since the characteristic equation proves to be valid, a method is presented for obtaining a specific sensitivity in sensor response by calculating the appropriate sourcing voltage and feedback resistor in the driving circuit; this provides plug-and-play capabilities to the device and reduces the start-up time of new applications where piezoresistive devices are to be used. Finally, a method for bypassing the amplitude nonlinearity is presented with the aim of reading sensor capacitance.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.