Weak Current Detection Technique for Electrostatic Droplet Ejection

For further researching on electrostatic droplet ejection, much detection methods have been studied. As the most direct and efficient approach, detection technique for weak current (level of nA) of the jetting is present in this paper. To observe and analyze the signals of electric current, detection system has been constructed. The parameters such as ejection frequency, ejection consistency can be investigated. By measuring the signal waveform, we can obtain that the appearance of a peak pulse indicates a droplet ejected to the counter electrode, and in the experimental condition of this work the asymmetric frequency of jetting ranged from few tens to around one thousand hertz. According to the results, this detection technique have proved to be feasible and valid for further researching on the electrostatic droplet ejection event and knowing more about the influence of various experimental parameters. Meanwhile, this detection method has a great potential as a technical condition of intelligent control of electrostatic droplet ejection.