Photolithographic fabrication of arbitrarily shaped SU-8 microparticles without sacrificial release layers

We report on an efficient high throughput method for the photolithographic fabrication of well-defined arbitrarily shaped SU-8 microparticles without a sacrificial release layer. The procedure eliminates the spincoating of a sacrificial layer otherwise needed for particle lift-off, thereby reducing processing time and costs. Statistical analysis of the size distribution revealed a standard deviation of less than 2.3% in size. The particles can be immediately released into aqueous solution. This allows for anisotropical functionalization of the particles with, for example, biological loads or elements of molecular recognition after the development of the SU-8 structures.