Multifunctional Flexible SnTe/MWCNT Crystalline Hybrid for Energy Storage and Humidity Sensing with 3D-Printed Device Integration

Abstract

The design of multifunctional materials that unify energy storage and environmental sensing is vital for next-generation flexible electronics and IoT devices. Here, a first report on Bridgman-grown polycrystalline SnTe/MWCNT (SUM) hybrid is presented, where the high pseudocapacitance of SnTe is synergistically coupled with the conductivity, flexibility, and porous architecture of carbon nanotubes. This hybrid serves as a dual-function platform, enabling both high-performance microsupercapacitors and humidity sensors fabricated via scalable screen-printing. The optimized asymmetric device (FAM-SUM-10) delivers an areal capacitance of 468.6 mF cm -2 , >95 % retention at high scan rates, and excellent cycling stability (98.7 % Coulombic efficiency over 5000 cycles) under mechanical deformation. As a humidity sensor, the same SUM-10 composite exhibits fast response (7 s), short recovery (9 s), and high sensitivity, further integrated into a 3D-printed wireless module for real-time monitoring. This work establishes Bridgman-assisted hybridization as a versatile route for scalable, flexible materials that bridge energy storage and environmental intelligence in wearable and precision sensing applications.