"flat" and "rigid" are terms typically usedto describe electronic devices. but the increasing demand for flexible, wearable electronics,sensors, antennas and biomedical devices has led a team at harvard’s wyss institute toinnovate an eye-popping new way of printing complex metallic architectures – as thoughthey are seemingly suspended in midair. this laser-assisted direct ink writing methodallows microscopic metallic, free-standing
how do 3d printers print metal, 3d structures to be printed in one step withoutauxiliary support material. the research team used an ink composed ofsilver nanoparticles, sending it through a printing nozzle and then annealing it usinga precisely programmed laser that applies just the right amount of energy to drive theink’s solidification. the printing nozzle
moves along x, y, and z axes and is combinedwith a rotary print stage to enable freeform curvature. in this way, tiny hemisphericalshapes, spiral motifs, even a butterfly made of silver wires less than the width of a haircan be printed in free space within seconds. the printed wires exhibit excellent electricalconductivity, almost matching that of bulk silver. when compared to conventional 3d printingtechniques used to fabricate conductive metallic features, laser-assisted direct ink writingis not only superior in its ability to produce curvilinear, complex wire patterns in onestep, but also in the sense that localized
laser heating enables electrically conductivesilver wires to be printed directly on low-cost
plastic substrates. this new method is opening up near limitlessnew potential applications in electronic and biomedical devices that rely on customizedmetallic architectures.
