NIST develops microscale rheometer

Researchers at the National Institute of Standards and Technology (NIST) recently demonstrated a microscale rheometer that can make complex viscosity measurements on material as small as a 5 nanoliters, NIST reported in 2010. The video shot by NIST shows the MEMS-based rheometer's moving plate, which is being controlled by resistance heating elements.

The moving plate is controlled by resistance heating elements in the chevron-like structure at the top; expansion and contraction of the vanes causes the plate to move up and down. Central square where the sample would rest is approximately 500 micrometers across. Video courtesy Christopher/NIST.

The device duplicates a classic sliding-plate dynamic rheometer—but in a space about one-twentieth the size of a postage stamp, NIST reported.

While early prototypes include only the core sliding plate mechanism and rely on a microscope and high-speed cameras for measurements, the NIST research team reported that "a more polished version" could include the necessary sensors on the chip, and the entire instrument reduced to a handheld device for such applications as quality control measurements on a plant floor.