Electron beam switched trapping and release of nanoparticles on nanopore array

We demonstrated switching of trap and release of nanoparticles using an inverted-electron beam lithography (I-EBL). 240-nm nanobeads suspended in pure water were trapped and released on nanopore array. The nanopores in a silicon nitride membrane generated trapping flows for the beads by infinitesimal leakages toward directly connected high vacuum via the nanopores. The incident electron beam selectively induced release of the trapping beads into the solution by Coulomb force.