In this paper, we present a low-cost, PDMS-membrane micropump with two one-way ball check-valves for lab-on-a-chip and microfluidic applications. The micropump consists of two functional PDMS layers, one holding the ball check-valves and an actuating chamber, and the other covering the chamber and holding a miniature permanent magnet on top for actuation. An additional PDMS layer is used to cover the top magnet, and thereby encapsulate the entire device. A simple approach was used to assemble a high-performance ball check-valve using a micropipette and heat shrink tubing. The micropump can be driven by an external magnetic force provided by another permanent magnet or an integrated coil. In the first driving scheme, a small dc motor (6 mm in diameter and 15 mm in length) with a neodymium-iron-boron permanent magnet embedded in its shaft was used to actuate the membrane-mounted magnet. This driving method yielded a large pumping rate with very low power consumption. A maximum pumping rate of 774 µL min −1 for deionized water was achieved at the input power of 13 mW, the highest pumping rate reported in the literature for micropumps at such power consumptions. Alternatively, we actuated the micropump with a 10-turn planar coil fabricated on a PC board. This method resulted in a higher pumping rate of 1 mL min −1 for deionized water. Although more integratable and compact, the planar microcoil driving technique has a much higher power consumption.

We present a robust low-cost PDMS peristaltic micropump with magnetic drive. The fabrication process is based on the soft molding and bonding of three PDMS layers. A base layer incorporates the microchannel while a middle layer contains the actuation membrane. The top layer encapsulates three small permanent magnetic rods (Ni-plated-NdFeB) in three small chambers. A small DC motor (6 mm in diameter and 15 mm in length) with three permanent magnets stagger-mounted on its shaft is used to pull down and actuate the membrane-mounted magnets to generate a peristaltic waveform. A maximum pumping rate of about 24 muL/min at the speed of 1700 rpm with power consumption of 11 mW was demonstrated. A preliminary numerical analysis of the peristaltic pump was performed, which showed the characteristic membrane deflection and fluid flow of pumping.

No abstract