MXene-Intercalated GO/MnO₂ via Layer-by-Layer Assembly for Highly Sensitive Wearable Capacitive Microsensors

The convergence of energy storage and sensing functionalities in a single miniaturized device represents a critical advancement for next-generation wearable electronics. Herein, we report an MXene/GO@MnO 2 composite with a rationally designed layer-by-layer architecture for planar microsupercapacitors (PMSCs) and capacitive microsensors. By intercalating MnO 2 -decorated graphene oxide (GO@MnO 2 ) between MXene layers, the interlayer spacing is expanded to 1.47 nm, enabling ultrafast ion diffusion ( D Li+ = 3.1 × 10 –12 cm 2 s –1 ) and efficient vertical electron transport (σ ⊥ = 247.7 S m –1 ). The resulting PMSCs achieve record-high areal capacitance (39.3 mF cm –2 ) and energy density (2.0 μWh cm –2 ) among MXene-based microdevices, with 91.1% capacitance retention after 10,000 cycles. As a wearable sensor, the device demonstrates multisignal detection capability, including temperature (10–40 °C, sensitivity = 6.3% °C –1 ), pressure (sensitivity >1.0 kPa –1, response time <10 ms), and biomechanical motions. This work provides a paradigm for designing multifunctional microsystems through strategic interlayer engineering of 2D materials.