Photoprintable Photothermal Actuators for Spatially Programmable Shape Morphing.

Abstract

Photothermal actuation holds great potential for developing smart materials capable of complex shape transformations. Conventional approaches to achieve these transformations often depend on selective light illumination or spatial engineering of mechanical modulus to induce localized responses, which lead to high design complexity and limited programmability. Using photocatalytic nanoparticles, we introduce a photoprintable strategy for fabricating photoactuators with spatially controlled plasmonic nanoparticle distributions and pattern line widths as small as 20 μm. This design enables localized photothermal heating and, therefore, complex, programmable shape morphing. To prove the concept, we demonstrate the construction of a bimorph actuator that can transform from a flat, two-dimensional shape to a three-dimensional helical form, capable of controlled object transport by mimicking the gripping behavior of tendril-climbing plants. Additionally, microscale photoprinting enables localized photothermal actuation that drives three-dimensional morphing and supports the miniaturization of soft actuators under uniform illumination. This photoprinting approach offers a straightforward yet effective platform for designing smart materials and devices with programmable and biomimetic shape transformations.