Technology: Enabling the Digital Scent

NevadaNano has spent a decade integrating multiple, complementary chemical sensors on a single silicon chip – we call it the Molecular Property Spectrometer™ (MPS™).  MPS™ sensors work together to measure a variety of thermodynamic and electrostatic molecular properties of sampled vapors, liquids, and particles. In less than a second, the chip creates a large, rich dataset of chemical information. Custom MPS™ software then identifies the types of molecules present in an unknown sample.

The chip is an example of a micro-electro-mechanical system (MEMS), and exploits the many inherent advantages of MEMS: low power consumption, minute size, light weight, and robustness for real world applications. For example, in a span of milliseconds the sensors can heat to hundreds of degrees Celsius, make a variety of high-precision thermal measurements, then cool back to room temperature. The system can detect picogram-scale masses and measure temperature with 0.01-degree resolution. It can operate in temperatures from -40°C to 70°C and all non-condensing humidity levels.

These capabilities make the MPS™ a highly flexible sensor solution, attractive for a wide range of applications.

The chip incorporates a patented array of microcantilevers with integrated piezoelectric sensing elements that provide electrical actuation and sensing of resonance frequency. Monitoring resonance is a highly sensitive way to measure very small masses of adsorbed analyte. The unique piezoelectric configuration of the MPS™ allows an array of sensors to be electrically monitored in a low-cost, robust fashion rather than using an optical readout (which is more common but more expensive and less robust).

All MPS™ sensors have built-in resistive heaters, used for an assortment of thermal analyses (e.g. Differential Scanning Calorimetry) and also for cleaning each sensor after processing a sample. When necessary, these resistors also enable temperature and flow compensation in order to minimize sensor noise and drift and further enhance sensitivity.