Nature May 20, 2025
Fiber-reinforced polymer composites are lightweight structural materials widely used in the transportation and energy industries. Current approaches for the manufacture of composites require expensive tooling and long energy-intensive processing resulting in a high cost of manufacturing limited design complexity and low fabrication rates. Here we report rapid scalable and energy-efficient additive manufacturing of fiber-reinforced thermoset composites while eliminating the need for tooling or molds. Use of a thermoresponsive thermoset resin as the matrix of composites and localized remote heating of carbon fiber reinforcements via photothermal conversion enables rapid in-situ curing of composites without further post-processing. Rapid curing and phase transformation of the matrix thermoset from a liquid or viscous resin to a rigid polymer immediately upon deposition by a robotic platform allows for the high-fidelity freeform manufacturing of discontinuous and continuous fiber-reinforced composites without using sacrificial support materials. This method is applicable to a variety of industries and will enable rapid and scalable manufacture of composite parts and tooling as well as on-demand repair of composite structures. Fiber-reinforced polymer composites are lightweight structural materials used in a wide range of applications but manufacturing of composites requires expensive tooling and long energy-intensive processing. Here the authors report rapid scalable and energy-efficient additive manufacturing of fiber-reinforced thermoset composites while eliminating the need for tooling or support materials.