Field-Driven Activation of Solid-State Devices in Open Circuits for Energy Harvesting and Wireless Sensing.

Time-varying electric fields induce displacement currents through capacitive coupling, resulting in current continuity even in the absence of conduction paths. While capacitive coupling is known as a parasitic effect, its role in directly activating solid-state devices in open circuits remains underexplored. Here, we demonstrate that externally generated, time-varying electric fields-produced by triboelectric excitation or moving charged objects-can directly activate linear and nonlinear components, such as diodes, rectifiers, and LEDs, without a galvanic connection. A lumped-element capacitive-coupling model captures the observed dependencies Vab∝ω and Vab∝1/r, validated experimentally on both linear and non-linear components. The resulting field-driven activation enables energy harvesting in open circuits, multi-channel control, and wireless sensing of human motion and mechanical vibrations over meter-scale distances. This quasi-static capacitive coupling operates in a distinct regime compared to resonant wireless power transfer, because it is drive by low-frequency, motion induced electric field changes that generate transient displacement currents in floating circuits. The findings here enable contact-free activation of electronic components through discrete energy transfer rather than traditional continuous power delivery.