Vibrating tube sensors: A versatile and low-cost instrument for continuously monitoring the mass, volume, and density of any microgram-sized biosample in fluid

An award is made to the University of California, Riverside, to develop a versatile and low-cost instrument for continuously monitoring the mass, volume, and density of any microgram-sized biosample in fluid. To maximize involvement of students from groups that are traditionally underrepresented in STEM fields (students who represent nearly half of the student body of UC Riverside), the project includes a program that will give 20 undergraduates the opportunity to assist with building beta versions of the proposed instrument for testing by bioscience collaborators.

This valuable career-readiness training will contribute to the development of a diverse and globally competitive STEM workforce. Additionally, by developing an open-source bioinstrument design suitable for replication by other researchers and future commercial production, the project will enhance the nation’s research infrastructure and lay the foundations for future partnerships between academia and industry.

Measurements of the mass of an object are ubiquitous throughout the sciences. But in the biosciences, many of the objects studied—like cells, microorganisms, fish embryos, insect larvae, sprouting seeds, hydrogels, oral pharmaceuticals, and many more—reside in a liquid environment. This makes it difficult or impossible to accurately measure the mass of these biosamples using conventional tools like laboratory balances.

In addition, the masses of many biosamples change in meaningful ways—an organism gains mass as it grows, a biodegradable material loses mass as it dissolves away, and so on—and accurately monitoring these mass changes over time is very labor-intensive. To address these gaps in biologists’ ability to capture observations of biological phenomena, this project will develop and disseminate a free and open-source design for an instrument capable of automatically monitoring the mass, volume, and density of any microgram-sized biosample, in any desired liquid, with nanogram-scale resolution.

The instrument utilizes a vibrating tube sensor, a simple piece of glass tubing vibrated at its resonance frequency. By passing a millimeter-sized biosample in fluid through this sensor, the mass of the sample is recorded as a change in the sensor’s resonance frequency. The instrument development process will be guided by feedback from a diverse set of five beta-testing bioscience research labs at UC Riverside who will use the instrument in toxicology, biomaterials, drug delivery, entomology, and plant science research.

The result will be a low-cost and easy-to-use instrument design that any bioscience researcher can replicate and use to monitor any suitably sized biosample, in any liquid, in a fully automated manner, over any desired timescale. This will give a diverse community of bioscience researchers a tool that not only supports and accelerates their existing research but also opens up whole new techniques and areas of inquiry.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.