Title :
Non-Contact Detection of Free Flying Nanoliter Droplets
Author :
Ernst, A. ; Streule, W. ; Zengerle, R. ; Koltay, P.
Author_Institution :
Univ. of Freiburg, Freiburg
Abstract :
In this paper we present a non-contact droplet sensor that allows for the detection of free flying liquid droplets with diameters in the range of 200-400 mum. The working principle is based on capacitive detection. The detector was fabricated cost-effectively in standard PCB-technology (printed circuit board) and characterized by experiments. Due to its small dimensions (18 times 56 times 1.6 mm) it can easily be placed into the flight-path of the liquid droplet when the distance between the dispenser and the target is at least 3 mm. The proposed sensor is able to detect any irregularity such as velocity, shape or volume variations in the droplet dispensing process by comparing the actual sensor signal with an average liquid specific "fingerprint". Therefore it is especially suited for online process monitoring in its present form.
Keywords :
capacitive sensors; drops; flow sensors; printed circuits; capacitive detection; capacitive sensor; dispensed liquid; droplet dispensing process; free flying liquid droplets; free flying nanoliter droplets; liquid specific fingerprint; noncontact detection; noncontact droplet sensor; online process monitoring; printed circuit board; size 200 mum to 400 mum; standard PCB-technology; Capacitance; Capacitive sensors; Capacitors; Frequency measurement; Liquids; Monitoring; Permittivity; Pollution measurement; Sensor phenomena and characterization; Transducers; capacitive sensor; contact less; dispensed liquid;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International
Conference_Location :
Lyon
Print_ISBN :
1-4244-0842-3
Electronic_ISBN :
1-4244-0842-3
DOI :
10.1109/SENSOR.2007.4300239
