State Key Laboratory of Dynamic Testing Technology, North University of China, Taiyuan 030051, China.
Taiyuan Institute of Technology, Taiyuan 030051, China.
Sensors (Basel). 2021 Jan 4;21(1):289. doi: 10.3390/s21010289.
As a new material, graphene shows excellent properties in mechanics, electricity, optics, and so on, which makes it widely concerned by people. At present, it is difficult for graphene pressure sensor to meet both high sensitivity and large pressure detection range at the same time. Therefore, it is highly desirable to produce flexible pressure sensors with sufficient sensitivity in a wide working range and with simple process. Herein, a relatively high flexible pressure sensor based on piezoresistivity is presented by combining the conical microstructure polydimethylsiloxane (PDMS) with bilayer graphene together. The piezoresistive material (bilayer graphene) attached to the flexible substrate can convert the local deformation caused by the vertical force into the change of resistance. Results show that the pressure sensor based on conical microstructure PDMS-bilayer graphene can operate at a pressure range of 20 kPa while maintaining a sensitivity of 0.122 ± 0.002 kPa (0-5 kPa) and 0.077 ± 0.002 kPa (5-20 kPa), respectively. The response time of the sensor is about 70 ms. In addition to the high sensitivity of the pressure sensor, it also has excellent reproducibility at different pressure and temperature. The pressure sensor based on conical microstructure PDMS-bilayer graphene can sense the motion of joint well when the index finger is bent, which makes it possible to be applied in electronic skin, flexible electronic devices, and other fields.
作为一种新材料，石墨烯在力学、电学、光学等方面表现出优异的性能，这使得它受到了人们的广泛关注。目前，石墨烯压力传感器很难同时兼顾高灵敏度和大压力检测范围。因此，人们非常希望能够制作出具有足够灵敏度、在宽工作范围内、工艺简单的柔性压力传感器。在此，通过将具有锥形微结构的聚二甲基硅氧烷（PDMS）与双层石墨烯相结合，提出了一种基于压阻效应的相对较高性能的柔性压力传感器。附着在柔性基底上的压阻材料（双层石墨烯）可以将垂直力引起的局部变形转化为电阻的变化。结果表明，基于锥形微结构 PDMS-双层石墨烯的压力传感器可以在 20 kPa 的压力范围内工作，同时在 0-5 kPa 的压力范围内保持 0.122 ± 0.002 kPa 的灵敏度，在 5-20 kPa 的压力范围内保持 0.077 ± 0.002 kPa 的灵敏度。传感器的响应时间约为 70 ms。除了压力传感器的高灵敏度外，它在不同压力和温度下还具有出色的可重复性。基于锥形微结构 PDMS-双层石墨烯的压力传感器可以很好地感应到食指弯曲时关节的运动，这使得它有可能应用于电子皮肤、柔性电子设备等领域。
