​The ability to accurately weigh tiny particles can provide valuable information about their nature, ultimately enabling new technologies, including for healthcare. The only thing missing is a precision instrument capable of detecting very low masses. CEA-Leti and MIT developed SNR* sensors—NEMS oscillators with microfluidic canals—that can be manufactured using techniques adapted from the semiconductor industry. Here's how they work: When a particle or molecule passes through the channel, the resonance frequency of the oscillator changes proportionally to the mass of that particle or molecule. This transient variation is then measured. It is effective at weighing particles as light as a single attogram (10^-18 g). More complex calculations can also be done to arrive at a particle's density or elasticity, for example.

Equipment and know-how developed during this joint research with MIT have now come back to CEA-Leti, where development of the future sensors will continue. The institute now has a new test bench that has been validated and is ready to use.
Ultimately SNRs could be used to detect exosomes, nanoscopic markers in the blood that are secreted by tumor cells, improving the early detection of certain cancers. Another potential use is the production of adenovirus-based vaccines and gene therapies. The researchers would also like to tackle the detection of even smaller objects, like protein aggregates, which could open the door to even more healthcare applications, including liquid biopsy biomarker detection for the diagnosis of neurodegenerative diseases.

*Suspended Nanochannel Resonator