Multilayer relaxor ferroelectric polymer stacks as data transmitter for real-time and programmable infrared information encryption

This work presents a multilayer relaxor ferroelectric polymer (RFP) stack capable of generating precise, real-time thermal waveforms for infrared (IR) information encryption. Using a bistable adhesion polymer (BAP) as a thermally switchable transfer medium, the authors construct multilayer P(VDF-TrFE-CFE) stacks without introducing inactive thermal loads, enabling up to eight layers bonded cleanly while preserving dielectric strength. Electrocaloric testing shows that each layer contributes additively to heat generation, producing a rectangular temperature wave between 22.1 °C and 26.3 °C under 80 MV/m, with rapid response rates (~0.012 s/K). The 8-layer stack maintains elevated temperature for ~8 s following field removal due to reduced convective heat dissipation. Infrared encryption demonstrations—including Morse-code signaling and a seven-segment IR display—highlight the system’s real-time programmability and speed advantages over thermochromic and electrochromic alternatives. This multilayer strategy establishes a scalable pathway to high-speed IR-based communication and encryption devices.