Photoactuation

Photoactuation is a phenomenon where materials undergo a mechanical change in response to light. This change can manifest as bending, stretching, shrinking, or other forms of movement. The underlying principle involves the absorption of photons by the material, which triggers a chemical or physical transformation. This transformation then leads to a macroscopic deformation.

Common mechanisms for photoactuation include photothermal effects, where absorbed light heats the material causing expansion or contraction, and photochemical effects, where light induces chemical reactions that alter the material's structure or properties. Photopolymerization is a well-known example of a photochemical photoactuation process, where light causes monomers to link together, leading to a change in shape or volume.

Photoactuators find applications in various fields, including microelectromechanical systems (MEMS), soft robotics, drug delivery systems, and adaptive optics. Their ability to respond to light offers advantages such as wireless control, precise actuation, and biocompatibility in some cases. Research in photoactuation focuses on developing materials with faster response times, larger displacement, and improved energy efficiency. The design of photoactuators often involves incorporating photoresponsive molecules or polymers into specific architectures to achieve desired motion.