Microfluidic actuation method and apparatus
AssigneeWisconsin Alumni Research Foundation
InventorsAmit Lal, Ville Kaajakari, Abhijit Sathaye
Life of this patent
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Abstract
Control of fluid motion within microcavities is carried out using microstructures in the cavities having cantilever elements that are coupled to a substrate to receive vibrations therefrom. The cantilever elements can be excited into resonance at one or more resonant frequencies. By selection of the shape of the cantilever elements, their position in the microcavity, the spacing of the cantilever elements from the walls of the cavity, and the frequency at which the cantilever elements are excited, the direction of pumping of fluid through the cavity can be controlled, blocked or diverted.
Claims26
Ultrasonic microfluidic actuation apparatus comprising:
- (a) a substrate;
- (b) structural material on the substrate defining a cavity having a bottom wall, side walls, and a top wall;
- (c) an ultrasonic actuator in the cavity having a cantilever element projecting into the cavity that is spaced from the bottom wall and the top wall of the cavity and that is coupled to the substrate to receive vibrations therefrom, the cantilever element having a resonant mode of vibration at a resonant frequency;
- and
- (d) an ultrasonic vibrator coupled to the substrate outside of the cavity to transmit ultrasonic vibrations to the substrate and from the substrate to the cantilever element.
Ultrasonic microfluidic actuation apparatus comprising:
- (a) a substrate;
- (b) structural material on the substrate defining a cavity having a bottom wall, side walls, and a top wall, wherein the height of the cavity from the bottom wall to the top wall is less than 100 μm;
- (c) an ultrasonic actuator in the cavity comprising a pedestal fixed to the substrate within the cavity and a cantilever element comprising a plate fixed to the pedestal and extending outwardly therefrom between the top wall and the bottom wall, the actuator coupled to the substrate to receive vibrations therefrom, the cantilever element having a resonant mode of vibration at a resonant frequency;
- and
- (d) an ultrasonic vibrator coupled to the substrate outside of the cavity to transmit ultrasonic vibrations to the substrate and from the substrate to the cantilever element.
A method of actuating fluid in microcavities comprising:
- (a) providing a microfluidic structure including a substrate, a structural material on the substrate defining a cavity having a bottom wall, sidewalls and a top wall, and an ultrasonic actuator in the cavity having a cantilever element projecting into the cavity that is spaced from the bottom wall and the top wall of the cavity and that is coupled to the substrate to receive vibrations therefrom, the cantilever element having a resonant mode of vibration at a resonant frequency;
- (b) providing fluid to the cavity;
- and
- (c) coupling an ultrasonic vibrator to the substrate and applying ultrasonic vibrations from the vibrator through the substrate to the ultrasonic actuator at a frequency that vibrates the cantilever element in a resonant mode of vibration.
Dependencies are inferred from the claim text.