Photothermal fixation of laser-trapped polymer microparticles on polymer substrates

Photothermal fixation of polymer microparticles onto a polymer substrate is demonstrated by using a laser manipulation technique. Individual microparticles were sequentially trapped by a 1064 nm Nd3+:yttrium–aluminum–garnet (YAG) laser light and pressed on a polymer substrate. Dye molecules that are doped into a substrate or dissolved into a solvent absorb the second harmonic pulse of a Nd3+:YAG laser and convert the absorbed light to thermal energy. It is considered that the local temperature elevation led to the local melting of the microparticle and substrate, resulting in mutual adhesion. The processes and microfixation conditions are presented, and the mechanism is discussed.