Peristaltic micropumps and fluid delivery devices that incorporate them
In one embodiment, a peristaltic micropump comprising a substrate having a first side and a second side, a microtube that extends across the first side of the substrate, and multiple pump actuators formed on the first side of the substrate and positioned adjacent to the microtube at discrete, spaced positions along the length of the microtube, wherein the micropump is configured to sequentially actuate the pump actuators so as to create peristaltic action that drives fluid contained in the microtube along the length of the tube.
1. A peristaltic micropump comprising:
a substrate having a first side and a second side;
a microtube that extends across the first side of the substrate;
multiple pump actuators formed on the first side of the substrate and positioned adjacent to the microtube at discrete, spaced positions along the length of the microtube, each pump actuator comprising a solid actuation member that is configured to expand when actuated;
wherein the micropump is configured to sequentially actuate the pump actuators so as to cause their actuation members to sequentially expand and sequentially compress the microtube to create peristaltic action that drives fluid contained in the microtube along the length of the microtube; and
one or more electrical contacts located on a surface of the substrate, the one or more electrical contacts used to supply power to the micropump.
2. The micropump of claim 1 , wherein the substrate comprises part of a printed circuit board.
3. The micropump of claim 1 , wherein an inner diameter of the microtube is no greater than 1000 microns.
4. The micropump of claim 1 , wherein each pump actuator comprises a pump actuator chamber that is open to the microtube and that contains the associated actuation member.
5. The micropump of claim 4 , wherein each pump actuator chamber and a chamber in which the microtube is provided are formed by the substrate, lateral elements formed on the substrate, and a top element formed on the lateral element.
6. The micropump of claim 1 , wherein the actuation members expand when heated.
7. The micropump of claim 6 , wherein each pump actuator further comprises a heating element configured to heat its associated actuation member and a temperature sensor configured to measure the temperature of the heating element.
8. The micropump of claim 1 , wherein the actuation members are solid masses of phase-change material that change phase and become liquid masses when heated to their melting points, the liquid masses comprising larger volumes than the solid masses.
9. The micropump of claim 1 , further comprising a microcontroller provided on the second side of the substrate, the microcontroller being configured to control the sequential actuation of the pump actuators to obtain the peristaltic action.
10. The micropump of claim 1 , wherein the actuation members are solid masses of shape-memory alloy.
11. An implantable fluid delivery device comprising:
a reservoir configured to contain a fluid to be delivered to a target site; and
a peristaltic micropump including a printed circuit board having a first side and a second side, a microtube that extends across the first side of the circuit board and to the reservoir, multiple pump actuators formed on the first side of the substrate and positioned adjacent to the microtube at discrete, spaced positions along the length of the microtube, each pump actuator including a solid actuation member that is configured to expand when actuated, and a microcontroller provided on the second side of the circuit board, the microcontroller being configured to control sequential actuation of the pump actuators that causes their actuation members to sequentially expand and sequentially compress the microtube to so as to create peristaltic action that drives the fluid contained in the reservoir along the length of the microtube.
12. The device of claim 11 , wherein the reservoir and micropump are encapsulated within a resilient polymeric material.
13. The device of claim 12 , wherein the device is approximately 2 to 6 mm thick, approximately 10 to 30 mm long, and approximately 6 to 12 mm wide.
14. The micropump of claim 11 , wherein the actuation members expand when heated.
15. The micropump of claim 14 , wherein each pump actuator comprises a heating element configured to heat its associated actuation member and a temperature sensor configured to measure the temperature of the heating element.
16. A method for delivering a liquid to a target site within an animal or human subject, the method comprising:
providing a fluid delivery device including a reservoir configured to contain the liquid to be delivered to the target site and a peristaltic micropump including a printed circuit board having a first side and a second side, a microtube that extends across the first side of the circuit board and to the reservoir, multiple pump actuators formed on the first side of the substrate and positioned adjacent to the microtube at discrete, spaced positions along the length of the microtube, each pump actuator comprising a solid actuation member that is configured to expand when actuated, and a microcontroller provided on the second side of the circuit board, the microcontroller being configured to control actuation of the pump actuators; and
sequentially actuating the pump actuators under the control of the microcontroller so as to cause their actuation members to sequentially expand and sequentially compress the microtube to create peristaltic action that drives the fluid contained in the reservoir along the length of the tube and to the target site.