Particle trapping in electrostatically actuated nanofluidic barriers

This paper introduces a device that can be applied to the trapping and analysis of nanoparticles in fluids. The device is fabricated on silicon substrates using standard microfabrication techniques. Sacrificial etching is used to form nanofluidic channels of precise dimensions. A section over these channels is made deformable by thinning the SiO₂ overcoat, and an electrode over the deformable section of these channels can be used to electrostatically constrict the channel walls. This deformed wall creates a physical barrier, which can trap and hold particles. Fluorescently labeled 50 nm diameter nanobeads are shown to trap behind pinched barriers in a 100 nm tall nanochannel.