The MEMS microsystem, a sensor developed by MIT in partnership with Leti, can rapidly determine cells’ mechanical signatures. The sensor is made up of around ten mechanical resonators—made by Leti in a 140-step process—mounted in parallel. 

The resonators have hollow cores, forming canals through which each cell passes individually. When a cell goes through a canal, it temporarily adds weight to the resonator, changing the resonance frequency, which is in turn measured by piezoresistive gauges. The differences in frequency measured are used to determine cell mass, density, and size—the cell’s signature. “When we add fluid to the canal, the time the cell takes to pass through the canal gives us additional information on the cell’s deformability and plasticity,” said a Leti researcher.

Once the cell’s mechanical signature has been determined, the flow can be reversed, so that the cell passes back through the canal. This feature can be used to observe changes in cell mass over time. “You can see how a cell’s mechanical behavior changes during cell division, for example, or when a drug is administered.” The MEMS could be used for very rapid antibiograms or to distinguish tumor cells from healthy ones.