Real-time Instrument Characterization Kit

Project Goal: Develop a benchtop demonstration system to show the feasibility of measuring volume dispensed for tissue staining systems using a capacitive sensor.

A key factor in tissue staining quality is the volume of reagent dispensed. A sensor platform that measures the volume dispensed allows the staining environment to be monitored, understood and controlled in real time throughout the staining process. This project presents a capacitive volume sensor to automate on-slide fluid volume measurements in real time.

This design uses a carefully defined sensing pattern on a printed circuit board to detect fluid on the surface of an adhered glass slide. It does so by measuring the change in capacitance of the system. A custom printed circuit and a capacitance-to-digital converter communicate with a custom graphical user interface on a host computer to report the volume sensed. Using a curve fit of experimental data, the capacitance is converted to volume and displayed as a graph on the graphical user interface.