Inventor: Pierre Lecomte du Noüy
How it began: The laboratory wanted to study surface tensions of various blood properties in order to understand wound healing. Methods then in use measured surface tension by calculating weight of hanging drops, a process that was time-consuming and made two readings necessary.
What it does: This instrument measures tension based on adherence to a platinum ring that is submersed in a liquid and slowly withdrawn. The tension on the wire counteracts the tension of the liquid and finally breaks it. As the ring is pulled out of the liquid into the air, the tension that is required can be precisely measured.
Impact on medical science: Because of its rapidity, simplicity and reliability, the instrument was widely adopted and is still used to measure surface tension of liquids.
Reference: Lecomte du Noüy, P. An interfacial tensiometer for universal use. The Journal of General Physiology, 1925, 7(5):625-633.
Photo by Lubosh Stepanek
Pierre Lecomte du Noüy, tensiometer, surface tensions