Photothermal Self-Healing, Magnetically Aligning Wearable Sensor System

Self-healing functionalities are studied actively in fields of stretchable electronics applications to improve the device lifespan, to gain economic feasibility, and ensuring environmental friendliness. However, the synthesis of high-efficient healing materials and specific application of these materials to actual devices are still in progress. In this abstract, we report on the fabrication of magnetic-aligning, light-responsive self-healing devices based on a custom-synthesized polyurethane(PU). Light-responsive self-healing PU was synthesized by reacting poly(tetramethylene ether) glycol, aminopropyl-terminated PDMS and aniline trimer. Aniline trimer inserted PU showed high photothermal property, increasing its temperature over 150°C when 808nm NIR laser is irradiated for several minutes. The glyoxime bond in PU chain dynamically regenerated when heated through NIR laser irradiation, exhibiting self-healing properties. Also, to acquire an automatic self-aligning property of self-healing devices, 5T-magnetized commercial ferrite rubber magnet was diced to 1mm-width rod shape and aligned to form in wanted magnetic flux. After patterning deformable magnet pattern in circular shape, the magnetic aligning layer was deposited into PU layer through liquid-casting method. After several hours of curing process, the magnetic pattern embedded in PU film was formed, showing self-aligning properties through attraction force between damaged magnetic patterns. Finally, the sensor device to measure biosignal and interconnection layer was embedded on polymer surface. The sensor system could be easily self-healed through magnetic-align and laser induced self-healing properties.