Laser assisted direct ink writing of planar and 3D metal architectures
Significance The growing demand for customized electronic devices underpins the need for 3D fabrication methods that enable form factors well beyond those that are flat and rigid. A printing method is introduced for one step fabrication of conductive and ductile metal features in planar and complex 3D shapes that combines direct ink writing with "on the fly" laser annealing. The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features "on the fly." To optimize the nozzle to laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.
Proceedings of the National Academy of Sciences