Modeling and Fabrication of Scalable Tactile Sensor Arrays for Flexible Robot Skins
Modeling and Fabrication of Scalable Tactile Sensor Arrays for Flexible Robot Skins
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DOI：
10.1109/jsen.2019.2915362
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发表时间：
2019-09-01
影响因子：
4.3
通讯作者：
Popa, Dan O.
中科院分区：
文献类型：
--
作者：
Saadatzi, Mohammad Nasser;Baptist, Joshua R.;Popa, Dan O.
具有多模态触觉反馈能力的人造机器人皮肤有望彻底改变机器人感知周围环境的方式，以及它们如何与人类合作完成比目前更复杂和动态的任务。开发触觉皮肤的努力必须解决与传感器的灵活性、鲁棒性和可扩展性相关的重大障碍。本文开发了一种柔性触觉传感器阵列，通过新型传感器几何形状和热补偿技术来解决这些障碍。这种触觉皮肤依赖于一种新型星形几何形状的聚合物压阻式应变计阵列。由于它们的径向对称性，所提出的应变片表现出对局部应变-应力加载的双轴响应，避免了单个tactels附近的“盲点”。该传感器使用金电极和压阻聚合物（PEDOT：PSS）微图案化的柔性聚酰亚胺基板上封装在一个顺应性的有机硅矩阵制造。首先使用多物理场有限元软件对传感器进行建模，以指导在各种负载分布和相对于仪表中心的位置下的各种几何参数的设计选择。提出了一种新的均匀热补偿技术，该技术将传感器封装在柔性载体的相对两侧。这种热补偿技术实现了10倍的温度漂移衰减以及应变测量方面的双重灵敏度。在数值建模之后，制造了具有通过模拟获得的最佳几何形状的4x 4触觉阵列，并将其连接到定制的电子数据采集系统。使用自动动态力实验测试台测试样品。触觉皮肤阵列的实验特征在于力灵敏度，空间响应，动态带宽和温度漂移。该阵列在0-0.5 N范围内的灵敏度为1125 nV/N，在0.5-23 N范围内的灵敏度为412 nV/N，滞后为11.13%，动态带宽为1.49 Hz，温度灵敏度为6 nV/摄氏度，在各个传感器中平均。
Artificial robot skins capable of multi-modal tactile feedback are anticipated to revolutionize how robots perceive their immediate surroundings and how they collaborate with humans on tasks that are more complicated and dynamic than currently possible. Efforts to develop the tactile skins must tackle significant hurdles related to flexibility, robustness, and scalability of sensors. In this paper, a flexible tactile sensor array is developed to address these hurdles via a novel sensor geometry and thermal compensation technique. This tactile skin relies on a polymeric piezoresistive array of strain gauges with a novel star-shaped geometry. Due to their radial symmetry, the proposed strain gauges exhibit a biaxial response to local strain-stress loading, avoiding "blind spots" in the vicinity of individual tactels. The sensors are fabricated using gold electrodes and piezoresistive polymers (PEDOT:PSS) micro-patterned on a flexible polyimide substrate enclosed in a compliant silicone matrix. The sensor is first modeled using multiphysics finite elements software to guide the design choices for a variety of geometric parameters under various load profiles and locations with respect to the gauge's center. A novel homogeneous thermal compensation technique is proposed, which packages the sensors on the opposite sides of a flexible carrier. This thermal compensation technique achieves a 10-fold attenuation in temperature drifts as well as a double sensitivity in terms of strain measurement. After numerical modeling, a 4 x 4 tactile array with the optimal geometry obtained through simulation was fabricated and interfaced to a custom-made electronic data acquisition system. Samples were tested using an automated dynamic force experimental test bed. The tactile skin array was experimentally characterized in terms of force sensitivity, spatial response, dynamic bandwidth, and temperature drift. The array exhibits a sensitivity of 1125 nV/N in the range of 0-0.5 N, a sensitivity of 412 nV/N in the range of 0.5-23 N, a hysteresis of 11.13%, a dynamic bandwidth of 1.49 Hz, and a temperature sensitivity of 6 nV/degrees C, averaged among individual sensors.