SOI基底上制备的用于检测机器人手指接触力的微压阻式力传感器

Micro-Piezoresistive Force Sensor for Detecting Robot Finger Contact Forces Prepared on SOI Substrates

为了使工业机器人可以稳定、高效地完成夹持任务,设计并制备了三种不同结构的微压阻式力传感器。利用热氧化、硼扩散掺杂、光刻、反应离子刻蚀、物理气相沉积和阳极键合等微电子机械系统(MEMS)加工工艺在绝缘体上硅(SOI)基底上制备出了尺寸均为2 mm×2 mm×0.5 mm的三种微压阻式力传感器。通过封装前后对三种传感器在z方向上的应力灵敏度测试,结果表明第二种传感器的灵敏度较佳,封装前可达0.18 mV/mN,封装后仍可达0.096 mV/mN,仅减少了0.084 mV/mN,仍具有良好的线性关系,输出特性的趋势与预计一致。同时,这三种不同结构的传感器各方向之间的串扰均小于5%,非线性小于满量程的3%。通过封装前后力传感器性能对比,为优化此类传感器设计提供了实验数据,为后续配置在机器人的指尖上实现高效、稳定的操作提供了参考。

To enable industrial robots to perform clamping tasks stably and efficiently,micropiezoresistive force sensors with three different structures were designed and prepared.Three micro-piezoresistive force sensors with the same dimension of 2 mm×2 mm×0.5 mm were prepared on silicon-on-insulator(SOI)substrates by using micro-electromechanical system(MEMS)processes such as thermal oxidation,boron diffusion doping,photolithography,reactive ion etching,physical vapor deposition and anodic bonding.The stress sensitivities of the three sensors in the z-direction before and after packaging were tested,The results show that the second sensor has a better sensitivity of up to 0.18 mV/mN before packaging and still up to 0.096 mV/mN after packaging,which is only reduced by 0.084 mV/mN.It still has a good linear relationship and the output characteristics trend as expected.Meanwhile,the crosstalk between all directions of the sensors with different structures is less than 5%,and the nonlinearity is less than 3%of the full scale.The comparison of the performances of force sensors before and after packaging provides experimental data for optimizing the design of such sensors and provides reference for the subsequent configuration to achieve efficient and stable operation at the fingertips of robots.