Machinery currently used to scan blood samples for harmful biological agents is expensive, bulky, and requires a great deal of electricity. However, a new membrane that efficiently pumps a sample through after exposure to electricity may pave the way for a chip-sized alternative. These electroosmotic pumps (EOPs) are needed for many applications, including by the Department of Defense and the Department of Homeland Security to identify compounds like anthrax in a person’s bloodstream.
The new membrane was developed at the University of Rochester and the findings were published this week by Proceedings of the National Academy of Sciences. The prototype pump is made from porous nanocrystalline silicon membranes and is only 15 nanometers thick when assembled; about one-thousandth the width of a human hair. This has amazing potential to make diagnostic tools that are no larger than a credit card.
The pump functions by placing the membrane and sample in between two electrodes. As the current begins to flow, electroosmosis occurs, pulling the liquid sample through. Because the membrane is so thin, it only requires one quarter of a volt to use, as opposed to the 10 kilovolts of traditional EOPs with thicker membranes that significantly drop the voltage. This will allow the new, smaller EOPs to require only a small battery, instead of an external power source, making it more portable and convenient during emergency situations.
While these new devices have the potential to revolutionize biomedical research the same principles can be applied to electronics. As electronic devices get smaller, the need for efficient cooling mechanisms gets increasingly difficult. Miniaturized EOPs could be used to protect these devices from overheating while only using a small amount of electricity.