Novel concept of a low-power high-volume microfluidic actuator: theory of operation and experimental characterization

• Published in: Sensors and Actuators. Part A, Physical Vol. 291; pp. 13 - 22
• Main Authors: Lavigne, Quentin, Terrier, Nicolas, Noetinger, Guillaume, Tran, Duc-Duy, Kulifaj, Simon, Kleimann, Pascal, Pittet, Patrick, Berge, Bruno
• Format: Journal Article Book Review
• Language: English
• Published: Lausanne Elsevier B.V 01.06.2019; Elsevier BV; Elsevier
• Subjects: Active eyeglasses; Actuation; Actuators; Anisotropy; Capacitance; Continuous flow; Deformation mechanisms; Electric potential; Electrodes; Electrostatic micro-pump; Electrostatics; Engineering Sciences; Eyewear; Formability; Metallizing; Micro and nanotechnologies; Microelectronics; Microfluidic actuator; Microfluidics; Optics; Photonic; Power consumption; Power supplies; Presbyopia; Pumping; Refractivity; Thin films; Active eyeglasses; Electrostatic micro-pump; Microfluidic actuator
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2019.03.018

[Display omitted] •New concept of liquid actuator based on a slack deformable metallized membrane.•Expectation of an increase of gap/thickness gain (>X100) in output pressure.•Full experimental characterization agrees with theory within ±15%. A novel concept of microfluidic actuator based on a slack metallized film confined between two parallel grid-electrodes separated by a gap is presented. The film is loosely attached such that it can move freely between the two grid-electrodes. Upon voltage application between the metallized film and one grid-electrode, electrostatic attraction tends to press the metallized film on the grid, thus pushing the fluid through the grid. This evolution happens through a film fold travelling across the cell width. Samples using a replication of grid-electrodes manufactured by silicon anisotropic etching have been assembled. An equilibrium theory of operation and an experimental characterization with measurements of exchanged liquid volumes, differential pressures, capacitance and applied voltage are presented, both agreeing within ±15%. It will be shown that actuators with an active zone of 8 mm x 45 mm and a gap of 0.25 mm can move 100 μl against differential pressures of about 200 Pa with a 100 V power supply at 100 Hz consuming few tens of mW. The only moving part is the deformable film and the actuator is silent when filled with liquids. The new concept also supports an accurate capacitance monitoring of the exchanged volumes. The actuation can be reversible by connecting one or the other grid electrode. This new pumping mechanism has been primarily designed for exchanging a given volume of two insulating fluids of different refractive indices, in order to activate ophthalmic variable eyeglasses for presbyopia correction. Nevertheless, the same concept can be extended to continuous flow pumping.