Single particle analysis with 2D electro-optical trapping on an integrated optofluidic device

Optical and optically assisted trapping has developed into an essential tool for studying and manipulating small objects with applications in numerous fields at the intersection of physics and the life sciences. Here, we report a waveguide based optofluidic platform which restricts particle movement in two dimensions for full in-plane suppression of Brownian motion based on fluorescence tracking and application of an electrokinetic feedback force. Single microbead trapping is demonstrated with confinement in two dimensions in a specially designed trapping volume. Tighter particle confinement and a 14x improvement in trap stiffness is achieved compared to 1D trapping along a fluidic channel. This paves the way for a chip-based high throughput single molecule analysis platform.