Open microdroplet diluter for concentration-gradient generation

Abstract

The requirement of producing concentration gradients rapidly and controllably is essential in many biochemical applications. The use of microdroplets is advantageous as the droplets act as isolated open reaction vessels that are proficient in containing a variety of reagents. We present a concept of producing concentration gradients over an array of open wells, using a concentrated primary drop which, whilst in motion, merges with successive buffer droplets and, as a result, leaves behind droplets of different concentrations. The primary drop is positioned to slide down a 90° incline over several secondary drops, whereby merging, mixing, and detaching occurs within each well.

Laser-induced actuation of individual microsize liquid metal droplets on an open solid surface

“…T he actuation of discrete microdroplets is critical in many emerging applications of micro-electromechanical systems (MEMSs), such as microfluidic devices and microswitches. 1,2) Actuation forces induced by electrowetting, 3,4) thermocapillary, 5) dielectrophoresis, 6) and magnetism 7) have been proposed to manipulate droplets. These actuation techniques typically require specific components or designs integrated into devices in order to fulfill their functions.…”