Thermal positioning of point defects in smectic films: The thermal tweezer

We have developed a simple, inexpensive, and easily incorporated technique for positioning point defects in free-standing smectic films, simplifying the study of defect structures in the moderate temperature window through probes such as depolarized reflected light microscopy. The technique exploits thermal flow in the smectic films to position and hold a point defect in place. We present details of the experimental design as well as measurements of the thermal flow induced by the device.