Light-based 3D printing method lets scientists program plastic properties at the microscale Researchers have co-developed a new way to precisely control the internal structure of common plastics during 3D printing, allowing a single printed object to seamlessly shift from rigid to flexible using only light. CRAFT builds on that principle by allowing researchers to control crystallinity spatially during printing, rather than uniformly throughout a part. The demonstrated ability to tune properties by changing a light’s intensity rather than swapping materials could significantly simplify additive manufacturing (3D printing), Schwartz explained. “If you can get many different properties from one vat of material, printing complex multi-material or multi-modulus structures becomes much easier,” she said. The researchers demonstrated the CRAFT technique on commercial 3D printers, fabricating objects that combine multiple mechanical behaviors in a single print.