‘Shocking’ 3D resin may build soft robots with plastic-like strength

Researchers at the University of Texas at Austin have developed an innovative 3D printing technique that uses a custom liquid resin and a dual-light system to create objects combining both soft, rubber-like flexibility and hard, plastic-like strength within a single print. Inspired by natural structures such as human bones and cartilage, this method employs violet light to produce flexible material and ultraviolet light to harden the resin, enabling seamless transitions between soft and rigid zones without weak interfaces. This breakthrough addresses common issues in multi-material printing where different materials often fail at their boundaries. Demonstrations of the technology included printing a functional knee joint with soft ligaments and hard bones that moved smoothly together, as well as a stretchable electronic device with flexible and stiff areas to protect circuitry. The researchers were surprised by the immediate success and the stark contrast in mechanical properties achieved. An adjacent study published in ACS Central Science further highlights the potential of light-driven resin chemistry to advance additive manufacturing, offering faster production, higher resolution, and new design freedoms.