Mechanically Tunable Metal–Insulator Transition in Flexible VO ₂ Devices for Ultra-Low Power Electronics

Vanadium dioxide (VO2) is a correlated oxide that undergoes a sharp, reversible metal–insulator transition (MIT) near 340 K, making it promising for energy-efficient electronics. However, integrating VO2 into flexible substrates with low power consumption via a straightforward approach remains a challenge. Here, we demonstrate the direct deposition of flexible VO2 thin films on Kapton via reactive magnetron sputtering. While applying a predeposited Al2O3 layer improves adhesion and strain control for flexible uses, the direct deposition also offers a straightforward procedure to produce freestanding VO2 films. The resulting flexible devices exhibit millimeter-scale resistive switching at submilliampere currents, showing two orders of reduction in power consumption compared to typical sapphire-based films. In operando midwave infrared imaging reveals filamentary conduction driven by Joule heating and local dissipation. Furthermore, we show that mechanical deformation modulates the resistance and can trigger the MIT under a preload voltage bias, enabling deformation-induced resistive switching. These results introduce a versatile and low-power consumption VO2 platform for flexible electronics, tactile sensors, and neuromorphic systems, offering functionalities through the synergy of correlated electron physics, thermal confinement, and substrate compliance.