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Electrohydrodynamic Atomization (EHDA), also known as Electrospray (ES), is a technology that uses a strong
electric field (kV/cm) to manipulate liquid breakup into droplets. This technique allows the generation of
monodispersed nano and micrometric size droplets. Depending on some conditions, different droplet
generation mechanisms can exist, known as “modes” by the EHDA community. The most known “mode” is the
cone-jet mode, mainly due to its stable operation and capability for monodispersed particle size production.
In this work, the author developed an automated electrospray system to expand the data acquisition capability
of electrosprayt systems, specially related to electric current data. The end goal is to further classify the
behavior of the electric current for different spray-mode as well as during spark events. The setup consists of
FUG power supply, HCP 14-20000, and an Aladdin AL-1000 pump that can both be controlled via USB serial
connections. The current is measured via an TiePie WifiScope WS6 that is a battery powered oscilloscope
capable of transmitting data via a WiFi connection allowing it to be placed in the high voltage or ground path.
The heart of the setup is the developed Python library allowing remote control of the power supply and pump,
as well as to acquire and process the measurement data from the oscilloscope.
The results of the collected data are further used for automatic classification of the spray Classification criteria
still have to be improved further. All datapoints are stored in JSON format along with liquid and setup data.
Choosing JSON as the desired format was driven by easy human readability over storage efficiency. A viewer
class allows visually browsing through blocks of data and manually verify and correct classifications. These
datasets can further be used to train a neural network for an alternative classification approach. The stored
data is also used to confirm existing relationships between quantities like e.g. current, fluid conductivity, flowrate,
Electrohydrodynamic Atomization (EHDA), also known as Electrospray (ES), is a technology which uses strong electric fields to manipulate liquid atomization. Among many other areas, electrospray is used as an important tool for biomedical application (droplet encapsulation), water technology (thermal desalination and metal recovery) and material sciences (nanofibers and nano spheres fabrication, metal recovery, selective membranes and batteries). A complete review about the particularities of this tool and its application was recently published (2018), as an especial edition of the Journal of Aerosol Sciences. One of the main known bottlenecks of this technique, it is the fact that the necessary strong electric fields create a risk for electric discharges. Such discharges destabilize the process but can also be an explosion risk depending on the application. The goal of this project is to develop a reliable tool to prevent discharges in electrospray applications.