This work presents a comprehensive near-field radiative thermal encryption platform that encodes symbolic information using tristate radiative heat-flux distributions across a two-dimensional array of gate terminals. The approach relies on temperature-programmed modulation of near-field radiative heat transfer enabled by phase-change materials placed on the gate of a thermal transistor. By encoding information into spatially varying gate temperatures, the net gate heat transfer can be tuned, which can be modulated and visualized to encode symbolic patterns. Specifically, the word “NEU” was used as an encryption target across several thermal pixels. A temperature permutation was designed to radiate outward from the shape, and radiative heat transfer at the gate was interpolated accordingly using precomputed temperature and radiation relations. To enhance clarity and digital readability, the map was discretized into square grid blocks, each representing an individual logical thermal cell. The results clarify the distinction between the near-field radiative thermal transistor, a physical three-terminal device, and near-field radiative thermal logic computing, the system-level architecture composed of many such devices for spatial logic and encryption. The results address many-body radiative interactions, lateral thermal diffusion, switching and energy considerations, and scalability pathways. Furthermore, the method avoids reliance on external toolboxes, enabling flexible implementation. This framework bridges near-field radiative thermal logic computation and symbolic encryption, offering another paradigm for contactless, reconfigurable, and visually interpretable heat-based information processing.
Zhang et al. (Mon,) studied this question.