Ni Na, Xue Xiaomin, Li Dongbo
School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Department of Civil Engineering, Xi'an Jiaotong University, Xi'an 710054, China.
Materials (Basel). 2021 Apr 1;14(7):1743. doi: 10.3390/ma14071743.
The soft sensing system has drawn huge enthusiasm for the application of soft robots and healthcare recently. Most of them possess thin-film structures that are beneficial to monitoring strain and pressure, but are unfavorable for measuring normal displacement with high linearity. Here we propose soft tactile sensors based on uniform-strength cantilever beams that can be utilized to measure the normal displacement and force of soft objects simultaneously. First, the theoretical model of the sensors is constructed, on the basis of which, the sensors are fabricated for testing their sensing characteristics. Next, the test results validate the constructed model, and demonstrate that the sensors can measure the force as well as the displacement. Besides, the self-fabricated sensor can have such prominent superiorities as follows-it is ultra-soft, and its equivalent stiffness is only 0.31 N·m (approximately 0.4% of fat); it has prominent sensing performance with excellent linearity (R = 0.999), high sensitivity of 0.533 pF·mm and 1.66 pF·mN for measuring displacement and force; its detection limit is as low as 70 μm and 20 μN that is only one-tenth of the touch of a female fingertip. The presented sensor highlights a new idea for measuring the force and displacement of the soft objects with broad application prospects in mechanical and medical fields.
软传感系统最近在软机器人和医疗保健应用方面引起了极大的关注。它们中的大多数具有薄膜结构，这有利于监测应变和压力，但不利于以高线性度测量法向位移。在此，我们提出基于等强度悬臂梁的软触觉传感器，可用于同时测量软物体的法向位移和力。首先，构建传感器的理论模型，并在此基础上制造传感器以测试其传感特性。其次，测试结果验证了所构建的模型，并表明传感器能够测量力和位移。此外，自制传感器具有如下突出优势——它超柔软，其等效刚度仅为0.31 N·m（约为脂肪的0.4%）；它具有出色的传感性能，线性度极佳（R = 0.999），测量位移和力的灵敏度分别为0.533 pF·mm和1.66 pF·mN；其检测极限低至70 μm和20 μN，仅为女性指尖触感的十分之一。所提出的传感器为测量软物体的力和位移提供了新思路，在机械和医疗领域具有广阔的应用前景。
