Multiple-spot optical tweezers created with microlens arrays fabricated by proton beam writing

Abstract

We report two different applications for using arrays of microlenses on glass substrate to facilitate multiple-spot optical trapping of colloidal microbeads. The array of microlenses was made of SU8 or PMMA resist and created by a combination of Proton-Beam writing followed by thermal reflow processes. Firstly, similar to previous reports, the lenses were utilized as an optical element in generating multiple laser spot arrays that were subsequently focused down to impose a microbead array. In addition, we demonstrated the feasibility of a novel approach of integrating the microlens array into a sample chamber to provide localized optical trapping.