Micropumping of Liquids by Directional Growth and Selective Venting of Bubbles

Compact design with no moving partsLow energy consumptionBiocompatibleApplicable in both open and closed-loop fluidic systemsWorks with virtually any means of gas bubble generation (e.g., electrolysis, gas injection, chemical reaction, and cavitation)

Small fuel cellsChromatographyBiological and chemical sensorsLab-on-a-chip microfluidic circuitsDrug delivery systems such as insulin pumps

This invention provides a compact means to pump a liquid in a microfluidic system by generating, moving, and quickly removing gas bubbles from the system with low power. With existing technology, bubble-driven pumps are made open so that bubbles are expelled with the liquid. In contrast, this invention vents the bubbles (without liquid) quickly through a nano-porous membrane making it applicable in both open and closed fluidic devices.

Patent Number: US7976286B2
Application Number: US2007814162A
Inventor: Kim, Chang-Jin | Meng, De-Sheng
Priority Date: 25 Jan 2005
Priority Number: US7976286B2
Application Date: 17 Jul 2007
Publication Date: 12 Jul 2011
IPC Current: F04F000118 | H01M000800
US Class: 417053 | 417208 | 417209 | 429400
Assignee Applicant: The Regents of the University of California
Title: Method and apparatus for pumping liquids using directional growth and elimination of bubbles | Method and apparatus for pumping liquids using directional growth and elimination bubbles
Usefulness: Method and apparatus for pumping liquids using directional growth and elimination of bubbles | Method and apparatus for pumping liquids using directional growth and elimination bubbles
Summary: For pumping fluid such as fuel in fuel cell (all claimed) such as micro direct methanol fuel cell.

化工/材料

燃料电池

7976286

State Of Development

A device has been fabricated, tested, and characterized in both closed-loop and open-loop configurations.

Other Information

ABOUT THE LAB:  This innovation is generated by the UCLA Micromanufacturing Laboratory at UCLA. Current research projects in the lab include digital microfluidics, nanoengineered surfaces, microdroplet-dispensing systems, RF liquid switches, micro fuel cells, 3-D microbatteries, and on-chip encapsulation of microdevices.

Website: http://cjmems.seas.ucla.edu/

 

Background

Micropumps are a critical element of microfluidics, as they are required to move small volumes of liquid in a controlled, energy-efficient manner. Several categories of micropumps have been reported, such as mechanical micropumps, electrokinetic micropumps, and valveless bubble-driven micropumps. The valveless bubble pumps are attractive for microfluidics because of their simplicity in fabrication over mechanical pumps and their flexibility in working liquids over electrokinetic pumps. The preferred method to date of generating bubbles in the valveless pump is by thermal generation (boiling). However, this method has several limitations. First, boiling requires high levels of energy to induce vapor formation. Second, the vapor condenses back to liquids much slower than they boiled, which limits the cycling speed of the pumping action. Another common bubble generation methods for the valveless pump is electrolysis, but they are not suitable for closed systems, such as fuel cells, because of the inability to eliminate the gas bubbles.

Additional Technologies by these Inventors

• Complete Transfer of Liquid Drops by Modification of Nozzle Design
• High-speed Switching of Droplet by Electric Meniscus Actuation
• Selective Surface Coating and/or Treatment of Printing Pins
• On-chip, Real-time Feedback Control for Electrical Manipulation of Droplets
• Localized Droplet Heating with Surface Electrodes in Microfluidic Chips
• No-Assembly Devices for Microfluidics Inside a Cavity
• Methods of Restoring and Maintaining Gas Film on Superhydrophobic Surfaces while Underwater
• Membraneless Fuel Cell with Self-Pumped Fuel and Oxidant
• Microstructured Cathode for Self-Regulated Oxygen Generation and Consumption
• Liquid-Repellent Surfaces Made of Any Materials
• A Low-Profile Flow Shear Sensing Unit
• Method for Commercial Production of Super-Hydrophobic Materials
• Method of Fluid Manipulation By Electrodewetting

Tech ID/UC Case

20152/2005-408-0

Related Cases

2005-408-0

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