Selective removal of micro-particles from a floating monolayer cluster

Self assembly is a very attractive way of creating two dimensional arrays of particles. One convenient method is to use the inter-particle forces which occur between particles of similar characteristics which float at a fluid gaseous interface. However, within populations of particles it is often beneficial to be able to remove rogue units. This work demonstrates that such selectivity is possible via the deposition of droplets in close vicinity to the particle whilst leaving the rest of the cluster largely undisturbed. With the accurate dispensing of droplets now achievable using technologies developed around the ink jet printer, this portends a useful method of sorting or removing rouge particles from clusters that form naturally due to capillary forces.