HeaTrace: A Parametric Design‐to‐Fabrication Workflow for Thermally Programmable Soft Robots

Inspired by the multifunctional bodies of natural organisms, soft robotic systems are advancing toward integrated body architectures that combine shape change, tunable compliance, and visual feedback within compact, material‐embedded structures. Thermal actuation provides a viable route to this multifunctionality by locally delivering heat from embedded Joule heaters to thermoresponsive materials. However, existing approaches treat heater geometry, conductive material, soft body design, and fabrication independently, limiting design flexibility and functional integration. This work presents HeaTrace, a design‐to‐fabrication workflow for thermally programmable soft robots that integrates parametric heater customization, a physics‐informed, semiempirical thermal model, and fabrication‐ready toolpaths for direct ink writing and automated fiber embedding. Controlled experiments on silicone substrates with embedded stainless‐steel yarn heaters quantify geometry and power‐dependent thermal performance from 5 to 15 W, heater durability, heat‐driven inflation, and stiffness modulation. The workflow is demonstrated through a gecko‐inspired soft robot achieving pump‐free inflation with a 6.5‐g thermally driven shape change actuator, a batoid‐inspired fin exhibiting 14% stroke asymmetry through programmable stiffness, and a humanoid face that expresses lifelike blushing. By integrating performance‐driven heater design with user‐defined functional materials and soft‐body geometries, HeaTrace opens a unified route to thermally programmable multifunctional soft robots.