Laser-Induced Forward Transfer: An Approach to Single-Step Polymer Microsensor Fabrication

Laser-induced forward transfer (LIFT) using a triazene polymer as dynamic release layer was used for the transfer of polyethyleneimine (PEI) pixels for microsensors applications. A XeCl laser was used to transfer the PEI pixels from a thin film coated onto the triazene layer. The PEI films were either in direct contact with the receiver or a gap was maintained between the donor film and the receiver. An optimization of the process was carried out by changing the laser fluences, the ratio between the thickness of the PEI and of the triazene layer, and the transfer distance. Welldefined, regular PEI pixels were obtained on the receiver. The morphology of the patterns was characterized using optical microscopy and scanning electron microscopy (SEM). The transfer onto surface acoustic wave (SAW) devices suggests that LIFT is a promising technique for the fabrication of microsensors with polymers as active layer.