The Physics of Digital Microfabrication with Molten Microdrops

Precise deposition of molten microdrops under controlled thermal conditions provides a means of 3D "digital microfabrication" , microdrop by microdrop, under complete computer control, much in the same way as 2D hard copy is obtained by ink-jet printing. This paper describes some results from a study of the basic modes of microdrop deposition and solidification (Gao & Sonin, 1993). The conditions required controlled deposition are discussed, and some experimental results and theoretical analyses are given for various basic deposition modes. These include columnar (Le. drop-on-drop) deposition at low and high frequencies, sweep deposition of continuous beads on flat surfaces, and repeated sweep deposition for buildup of larger objects or materials.