Most conventional 3D printing processes rely on replicating a digital design model that is sliced into layers with the layers printed and assembled upward like a cake. A new method introduces the ability to manipulate the original design layer-by-layer and pivot the printing direction without recreating the model. This “on-the-fly” feature enables the printing of more complicated structures and significantly improves manufacturing flexibility.
The dynamic process uses light to assemble the layers but with a high degree of freedom to move each layer along the way. The researchers demonstrated several applications including 3D printing a customized vascular stent and printing a soft pneumatic gripper made of two different materials: one hard and one soft.
The process uses a robotic arm and a liquid photopolymer that is activated by light. Sophisticated 3D structures are pulled out from a bath of liquid resin by a high-precision robot with enhanced geometric complexity, efficiency, and quality compared to the traditional printing process. The arm is used to change the printing direction dynamically.
Shining light on the liquid polymer causes it to crosslink, or polymerize, converting the liquid to a solid. This contributes to the speed and precision of the 3D printing process. The continuous printing process can print 4,000 layers in approximately two minutes. The general printing method is compatible with a wide range of materials.
The researchers believe the printing process could be applied to other additive as well as traditional subtractive manufacturing processes, providing a bridge toward a truly hybrid process.