Electroactive hydrodynamic weirs for microparticle manipulation and patterning.

We present a platform for parallelized manipulations of individual polarizable micron-scale particles (i.e., microparticles) that combines negative dielectrophoretic forcing with the passive capture of hydrodynamic weir-based trapping.

A photopatternable silicone for biological applications.

We show the application of a commercially available photopatternable silicone (PPS) that combines the advantageous features of both PDMS and SU-8 to address a critical bioMEMS materials deficiency. Using PPS, we demonstrate the ability to pattern free-standing mechanically isolated elastomeric structures on a silicon substrate: a feat that is challenging to accomplish using soft lithography-based fabrication. PPS readily integrates with many cell-based bioMEMS since it exhibits low autofluorescence and cells easily attach and proliferate on PPS-coated substrates.

Quantitative modeling of dielectrophoretic traps.

We present quantitative modeling software for simulating multiple forces acting on a single particle in a microsystem. In this paper, we focus on dielectrophoretic (DEP) trapping of single cells against fluid flow. The software effectively models the trapping behavior for a range of particles including beads, mammalian cells, viruses, and bacteria.

A scalable addressable positive-dielectrophoretic cell-sorting array.

We present the first known implementation of a passive, scalable architecture for trapping, imaging, and sorting individual microparticles, including cells, using a positive dielectrophoretic (p-DEP) trapping array. Our array-based technology enables "active coverslips" where, when scaled, many individually held cells can be sorted based upon imaged spatial or temporally variant characteristics. Our design incorporates a unique "ring-dot" p-DEP trap geometry organized in a row/column array format.