Researchers from the National Institute of Standards and Technology (NIST) and University of Colorado Boulder (CU) developed a new chip that uses microfluidics and magnetic switches to trap and transport magnetic beads. This low-power device may be useful for medical devices. This technology may also lead us towards "MRAM" chips used for molecular and cellular manipulation.
In the past, magnetic particle transport chips required continuous power and even cooling. This new technology manages to overcome the power and heat issues, and offers random-access two-dimensional control and non-volatile memory. The prototype chip uses 12 spin valves (commonly used as magnetic sensors in HD read heads) which are optimized for magnetic trapping. Pulses of electric current are used to switch individual spin valve magnets “on” to trap a bead, or “off” to release it, and thereby move the bead down a ladder formed by the two lines. The beads start out suspended in salt water above the valves before being trapped in the array.