Smart wearable band-aid integrated with high-performance micro-supercapacitor, humidity and pressure sensor for multifunctional monitoring

Band-aids, which possess breathable woven fabric and a compressible cotton pad, can be a potential substrate for smart wearable electronics. However, integrating energy storage modules and multiple functions into commercial band-aids through a simple and practical method is still a huge challenge. In this work, we design a multifunctional intelligent wearable band-aid, which integrates the high-performance micro-supercapacitor (MSC) with humidity and pressure sensors, through a facile laser-scribing and single-wall carbon nanotubes (CNT) drop-casting strategy. As a proof of concept, the fabricated laser-induced sulfur-doped porous graphene-based MSC on the band-aid surface offers an excellent areal capacitance of 68.6 mF cm−2 and good cyclic stability. Also, the designed humidity sensor has a fast and reversible real-time response and a wide relative humidity (RH) sensing range (11–97% RH). Remarkably, the obtained capacitive pressure sensor has a high sensitivity of 25.15 kPa−1, an ultra-broad linear range (0 ∼ 300 kPa) and a low limit of detection of 2.92 Pa. This proposed band-aid based multifunctional integrated system paves a new avenue for the development of smart wearable and flexible electronics.