Direct Writing of Semiconducting and Conducting Microstructures by Using Selective Laser Sintering and Reduction of CuO Nanoparticles

Additive and subtractive manufacturing and selective reduction of CuO microstructures were realized and investigated by employing a femtosecond laser. The changes of the morphologies and cross section shapes of additively manufactured CuO wires were systematically analyzed, and a CuO microstructure with a feature width of 947 nm was fabricated by using a hybrid method of selective laser sintering and ablation. The fabricated CuO microstructures were further reduced to conductive Cu microstructures by using selective laser-induced chemical reduction. The feature size, composition, and electrical performance of the fabricated Cu microstructures were studied. Cu microwires with electrical resistivities of about 8.76 × 10–7 Ω·m were achieved, and several Cu and CuO/Cu composite microstructures were also fabricated by using the combined method of selective laser sintering and reduction. This hybrid and combined manufacturing method provides a flexible, low-cost, and accurate protocol for fabricating CuO, Cu, and their composite microstructures.