Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Sci Robot. 2022 Jun 8;7(67):eabm7187. doi: 10.1126/scirobotics.abm7187.
Human skin perceives physical stimuli applied to the body and mitigates the risk of physical interaction through its soft and resilient mechanical properties. Social robots would benefit from whole-body robotic skin (or tactile sensors) resembling human skin in realizing a safe, intuitive, and contact-rich human-robot interaction. However, existing soft tactile sensors show several drawbacks (complex structure, poor scalability, and fragility), which limit their application in whole-body robotic skin. Here, we introduce biomimetic robotic skin based on hydrogel-elastomer hybrids and tomographic imaging. The developed skin consists of a tough hydrogel and a silicone elastomer forming a skin-inspired multilayer structure, achieving sufficient softness and resilience for protection. The sensor structure can also be easily repaired with adhesives even after severe damage (incision). For multimodal tactile sensation, electrodes and microphones are deployed in the sensor structure to measure local resistance changes and vibration due to touch. The ionic hydrogel layer is deformed owing to an external force, and the resulting local conductivity changes are measured via electrodes. The microphones also detect the vibration generated from touch to determine the location and type of dynamic tactile stimuli. The measurement data are then converted into multimodal tactile information through tomographic imaging and deep neural networks. We further implement a sensorized cosmetic prosthesis, demonstrating that our design could be used to implement deformable or complex-shaped robotic skin.
人体皮肤可以感知施加于身体的物理刺激，并通过其柔软且有弹性的机械特性来减轻物理相互作用的风险。社交机器人如果能够拥有类似人体皮肤的全身机器皮肤（或触觉传感器），将有助于实现安全、直观和丰富接触的人机交互。然而，现有的软质触觉传感器存在几个缺点（复杂的结构、较差的可扩展性和易碎性），限制了它们在全身机器皮肤中的应用。在这里，我们介绍了一种基于水凝胶-弹性体混合体和层析成像的仿生机器皮肤。所开发的皮肤由坚韧的水凝胶和硅酮弹性体组成，形成一种仿皮肤的多层结构，具有足够的柔软度和弹性，可实现保护功能。即使在严重损坏（切口）后，传感器结构也可以用粘合剂轻松修复。对于多模态触觉感知，在传感器结构中部署了电极和麦克风，以测量由于触摸引起的局部电阻变化和振动。由于外力，离子水凝胶层会发生变形，通过电极测量由此产生的局部电导率变化。麦克风还检测来自触摸的振动，以确定动态触觉刺激的位置和类型。然后通过层析成像和深度神经网络将测量数据转换为多模态触觉信息。我们进一步实现了一个带有传感器的美容假体，证明了我们的设计可以用于实现可变形或复杂形状的机器人皮肤。
