Resonant Mass Measurement

The technique of resonant mass measurement (RMM) to count and characterize particles is the heart of Malvern’s Archimedes – with its unique  MEMS (micro electro-mechanical systems) sensor.

Two types of sensor are available at present,  the Micro sensor and the Nano sensor, to suite your applications. Each sensor comprises a microfluidics network and a minute cantilever which resonates with a particular frequency. Embedded in this cantilever is a microfluidic channel. As the advanced fluidics system of Archimedes pushes sample through this channel, the resonant frequency of the cantilever alters. This shift in the frequency of resonance is measured by a laser, focused on the tip of the cantilever, which is then transmitted to a split photodiode detector.

Each particle which passes through the sensor causes a change in the resonant frequency, giving an accurate and precise measurement of the particle’s buoyant mass – whether positive or negative – in the sample. From this measurement, the mass, size (equivalent sphere), and surface area of the particle are calculated. Overall measurements are also made of sample concentration, density, volume, and polydispersity.


RMM - Archimedes sensors                 Diagram 3


Manufacturer Product
Malvern web site Archimedes