Three-Dimensional Stacked Stretchable Thermoelectric Device for Virtual Sensation.

Stretchable electronics have significant applications in wearable applications. However, the extremely low thermal conductivity of elastic encapsulation hinders heat dissipation, leading to performance degradation. For instance, stretchable thermoelectric devices (TEDs) can be used for skin temperature regulation, but poor thermal management limits their cooling performance. This article proposes advanced material and fabrication optimization for stretchable TED with a three-dimensional structure, achieving enhanced performance through the stacked integration of multilayer thermoelectric unit networks. Techniques such as laser ablation are employed to create thermal vias, significantly improving interlayer thermal exchange efficiency. The resulting device can achieve 30% stretching and provides a stable and long-term 10 °C skin cooling under normal arm movement. Additionally, by integrating temperature sensing and control circuits, the fabricated wearable closed-loop system can programmatically regulate skin temperature, suitable for virtual temperature and pain sensation. The 3D integration method and thermal via construction technique proposed in this article can also be applied to other high-power stretchable electronics.