Highly stretchable integrated system for micro-supercapacitor with AC line filtering and UV detector

In-plane micro-supercapacitors (MSCs) possess higher volumetric energy density and are thus more compact compared with traditional aluminum electrolytic capacitors (AECs). As a result, developing in-plane MSCs with AC line filtering function is desired to replace the AECs and integrate with other electronic devices. Here, highly stretchable integrated system for in-plane MSCs with AC line filtering and UV detector were fabricated by designing buckled micro-electrodes based on SWCNT film and TiO2 NPs. Although gel electrolyte was used in these MSCs, they still show an ultrafast frequency response with a phase angle of -75.2 degrees because of their unique structure. Such MSCs thus can function as the AC line filtering devices. Furthermore, their AC line filtering behavior remains almost unchanged even stretched up to 200%. Further coating TiO2 NPs on the buckled SWCNT micro-electrodes is able to endow the MSCs with another ability of UV photodetection with the sensitivity of 6.2. Importantly, such integrated device can still show stable photocurrent response and capacitance behaviors at different stretching times and even repeated stretching 100 times. The rational design of such stretchable integrated system for MSCs with AC line filtering and UV photodetector will pave the way for the applications in assembling supercapacitors and other electronics into highly stretchable integrated devices.