Magnetocaloric pump for microfluidic applications

Abstract

A microfluidic magnetocaloric pump. The magnetic and thermal properties of a ferrofluid such as MnZnFe2O4 nanoparticles in an oil- or water-based medium are allowed to interact with a magnetic field that is partially coincident with a thermal gradient. As the ferrofluid heats, it loses its attraction to the magnetic field and is displaced by cooler fluid. The micropump produces fluid propulsion with no moving mechanical parts while requiring only 35 mW power and operation at a temperature of only 40-80° C.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0001] The United States Government has rights in this invention pursuant to Contract No. DE-AC05-00OR22725.between the United States Department of Energy and UT-Battelle, LLC.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to microfluidic pumps. More particularly, a magnetocaloric pump incorporated into an integrated circuit chip utilizes MnZnFe2O4 ferrofluid. The micropump requires only 35 mW power and operates at a temperature of only 40-80° C. [0004] 2. Description of the Prior Art [0005] Microfluidic and lab-on-a-chip devices usually require some form of fluid pumping mechanism. While a great many pumping methods are known, there are only two basic approaches to pumping fluid at the microfluidic level. These are diaphragm and field-induced pumps. Diaphragm pumps use a small diaphragm on the chip that undergoes deformation to move the fluid. Passive valves or restric...

AI Technical Summary

Problems solved by technology

There are two limitations to such approaches.

First, the fluid flow is not continuous but pulsating.

Second, the pump deforms a membrane at high frequency.

Material fatigue limits the life cycle of the pump.

While this approach provides smooth flow, it generally requires high voltage which impacts electronics packaging and increases the overall system packaging size.

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