Spatiotemporal Thermal Modulation and Patterning using a Programmable 1024 Element Microheater Array

Programmable microheater arrays are essential for a variety of applications including gas sensing, microfluidic lab-on-a-chip devices, 3D printers, and biosensors that rely on DNA amplification. Increasing the density and number of heating elements directly correlates with the precision with which spatiotemporal heat profiles can be delivered. However, large arrays have thus far not been realized. One challenge is that as the number of elements in an array increases, the complexity of connecting them grows. Here, we show that row-column addressing provides a promising architecture for the efficient operation of a large microheater array. We introduce a programmable $32\times 32$ microheater array consisting of individually addressable robust platinum (Pt)-based Joule heating elements - each smaller than 300 $\mu m$ . We show that combining high-voltage multiplexed electronics and sequential addressing controlled by a high-frequency clock, allows the independent operation of the 1024 microheater elements. We demonstrate the generation of heat images and the patterning of metallic structures formed from the liquid metal Gallium. Our work demonstrates new capabilities for on-chip thermal devices, and opens the possibility to realize novel heat-controlled micro actuation systems.