Materials and Device Techniques for Electronic Skins with Intrinsic Stretchability

Electronic skin (e-skin) refers to the electronic devices that mimic the functionalities of human skin, such as their physical attributes and capabilities of sensing diverse stimuli including but not limited to tactile, temperature, humindity, and etc. These e-skin devices can also be used to sense physiological signals and provide appropriate feedback therapy, when equipped with proper modules. For either purpose, it is imperative that the e-skin devices conform to the dynamic surfaces of the human skin and deform freely following the daily activities of our body, in terms of improving the quality and accuracy of the retrieved biosignals and providing sustainable operation over prolonged amounts of time. Thus, a soft and deformable nature is required for the e-skin devices, and advancements in intrinsically stretchable materials and device technologies have led to the creation of e-skin devices that closely mimic the mechanical properties of the skin. This similarity facilitates their seamless integration and enhances their long-term stability. In this article, we offer a concise overview of these stretchable materials and the related device technology, particularly highlighting their use in robotic and biomedical e-skin applications.