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Abstract:We present laser-induced forward transfer of solid-phase polymer films, shaped using a Digital Micromirror Device (DMD) as a variable illumination mask. Femtosecond laser pulses with a fluence of 200-380 mJ/cm 2 at a wavelength of 800 nm from a Ti:sapphire amplifier were used to reproducibly transfer thin films of poly(methyl methacrylate) as small as ~30 µm by ~30 µm with thickness ~1.3 µm. This first demonstration of DMD-based solid-phase LIFT shows minimum feature sizes of ~10µm.

We have demonstrated the fabrication of a thermoelectric energy harvesting device via laser-induced forward transfer of intact solid thin films. Thermoelectric chalcogenide materials, namely bismuth telluride (Bi2Te3), bismuth selenide (Bi2Se3) and bismuth antimony telluride (Bi0.5Sb1.5Te3), were sequentially printed using a nanosecond excimer laser onto an elastomeric polydimethylsiloxane-coated glass substrate to form thermocouples connected in series creating a thermoelectric generator. The resulting generator Seebeck coefficient and series resistance per leg pair were measured to be 0.17 mV K−1 and 10 kΩ respectively. It was shown that laser-induced forward transfer allows device fabrication from inorganic semiconductor compounds on inexpensive elastic polymer substrates and demonstrates the ability to print materials with pre-defined thermoelectric properties. This allows the rapid manufacturing of a complete thermoelectric device on mm2-areas with μm-scale precision, without the need of further lithographic steps.

We present a rapid technique for the patterning of complex structures with ~2µm resolution via multiphoton polymerization, through use of a single ultrashort pulse in combination with the spatial intensity modulation possible from a digital multimirror device. Sub-micron features have been achieved through the use of ten consecutive pulses.