Large-Scale Fabrication of Flexible On-Chip Micro-Supercapacitors by a Mechanical Scribing Process

On-chip micro-supercapacitors (MSCs) as efficient miniaturized energy storage devices have attracted great attention for potential application in flexible electronics. In this work, a facile and low cost mechanical scribing method was designed to fabricate flexible all-solid-state on-chip MSCs arrays with ZnCo₂O₄ nanowires as the interdigitated electrodes, PVA/KOH as solid-state electrolyte and Ag nanowires as current collector. The fabricated single on-chip MSC is composed of 10 microelectrodes organized in an interdigitated planar geometry with the area of ∼1.05 cm². Studies found that a single device can achieve a high areal energy density of 0.065 μWh cm⁻² at 0.092 mW cm^−2. The mechanical flexibility of the MSC is robust, only 1 % change was observed in capacitance when going through 2000 mechanical bending cycles. Furthermore, a multi-functional nano/micro-system was configured by integrating the on-chip MSC as the energy unit and CdS nanowire-based photodetector as the functional detecting unit. In the integrated system, the on-chip MSC provides similar power supplier for the photodetectors as the conventional external energy unit, demonstrating the feasibility and potential application of the on-chip MSCs for next generation flexible electronics.