High-resolution dynamic thermal programming platform based on micro thermoelectric device assisted by laser integrated manufacturing

Thermoelectric devices (TEDs) exhibit much application potential in thermal camouflage and encrypted display recently, requiring that TEDs possess large responsivity, high resolution and rapid response with flexible configuration design, which are hardly realized by the traditional complex fabrication process. In this work, an innovative laser integrated manufacturing technology including double-side-printing selective laser melting (D-SLM) and selective laser ablation (SLA) is developed for the construction of the dynamic thermal platform based on micro TEDs. Through experimentally determining the laser process window assisted by external temperature field regulation, a flat p-type film can be directly transformed from n-type Bi₂Te₃ film by D-SLM. Thus, high-precision p-n patterns without metal joints are obtained from a single locally modified film, whose thermoelectric properties are further boosted by increasing energy density and introducing a post-annealing process. Then, a dynamic thermal platform with designable shapes and small dimensions can be fabricated rapidly whose working principle is also demonstrated. The thermal platform with 4*4 arrays exhibits imaging function with a pixel size of 2 mm×2 mm, a temperature difference of ∼3 K, and a fast response time of 0.143 s. This work offers an exciting yet effective approach to fabricating TEDs for dynamic thermal programmable information displays.