MICRODROPLET MANIPULATION DEVICE

A device for fast manipulation of many thousands of microdroplets simultaneously using optically-mediated electrowetting is provided. The device comprising: a first composite wall comprising: a first substrate (2b); a first transparent conductor layer (3) on the first substrate (2b) having a thickness in the range 70 to 250 nm; a photoactive layer (5) activated by electromagnetic radiation in the wavelength range 400-1000 nm on the first transparent conductor layer having a thickness in the range 300-1000 nm and a first dielectric layer (6) on the photoactive layer having a thickness in the range of 120 to 160nm; and a first anti-fouling layer (7) on the first dielectric layer; a second composite wall comprising: a second substrate (2a); a second conductor layer (3) on the second substrate having a thickness in the range 70 to 250 nm; and a second dielectric layer (6) on the second conductor layer; and a second anti-fouling layer (7) on the second dielectric layer the device further comprising: one or more spacers for holding the first and second walls apart by a pre-determined amount to define a microfluidic space adapted to contain microdroplets, wherein the spacer comprises a bead, a pillar or a ridge; an A/C source (4) to provide a voltage of between 10V and 50V across the first and second composite walls connecting the first and second conductor layers so as to be below the dielectric breakdown voltage of the first and second dielectric layers (6); at least one source of electromagnetic radiation (8) having an energy higher than the bandgap of a photoexcitable layer adapted to impinge on the photoactive layer (5) to induce corresponding ephemeral electrowetting locations (11) on the surface of the first dielectric layer (6); and a microprocessor (12) for manipulating points of impingement of the electromagnetic radiation on the photoactive layer so as to vary the disposition of the ephemeral electrowetting locations (11) thereby creating at least one electrowetting pathway along which microdroplets may be caused to move; wherein the device is configured to performing chemical analyses carried out on multiple analytes simultaneously.