Precisely controlled microdroplet merging by giant-electrorheological-fluid-based microvalve

A microfluidic device with a microvalve incorporated intelligent giant electrorheological fluid (GERF) was proposed to actively and accurately control micro-droplet merging in various droplet scales. The GERF is suspension without an additional electric field, its viscosity can be increased the increase voltage. chamber composed of expanded channel thin membranes on both sides several pillars used realize merging. restrict flow ensure contact. When pressure applied by microvalve, would pump up chamber. Thus, difference between could controlled membranes’ deformation influence droplets. Therefore, number merged droplets from zero five when rate continuous phase discrete 0.5 µl/min or four 0.8 0.2 µl/min. micro-chip easily fabricated complex equipment, only pair electrodes are required microvalve. has excellent application prospects chemical synthesis single-cell analysis.