Figure 3.

Schematic representation of the TRPS instrument.

A voltage is applied across a stretchable membrane containing a pore (A). The dynamic range of the instrument can be tuned to match the particle properties by stretching the membrane to change the pore diameter (B). The current across the membrane is monitored and will drop as particles pass through the pore, momentarily increasing its electrical resistance (C). The number of events can be used to calculate the concentration and the magnitude of the event used to develop a size distribution.