1. Intro
This project focuses on developing an atmospheric plasma jet system tailored for precise, repeatable surface modification. By integrating the plasma torch with a modified 3D printer frame, we’ve created a motion-controlled platform capable of executing programmable treatment patterns across a range of materials. The system enables fine control over plasma exposure for applications such as surface activation, thin-film adhesion, and sensor substrate modification—critical steps in advancing flexible optoelectronic devices.
2. How I built this
We began by designing and assembling a plasma jet setup using an atmospheric torch and an RF power supply. To gain precise spatial control over the plasma-surface interaction, we retrofitted a standard 3D printer frame to serve as an XYZ gantry for the jet. This allows for G-code-controlled movement, enabling repeatable scan paths and treatment routines.
To monitor plasma behavior during operation, we mounted an SMA-terminated fiber optic cable aligned with the jet and connected it to an Ocean HDX Mini spectrometer. This optical emission spectroscopy (OES) setup allows us to collect time-resolved plasma emission data during treatment cycles (see image below). The software was configured to log spectra at regular intervals, enabling us to correlate treatment parameters with plasma characteristics in real time.
OES Fixture for real-time emissions monitoring of plasma jet.
3. What it does
The system delivers spatially controlled atmospheric plasma treatment to surfaces with micron-level positioning accuracy. Users can define movement paths and exposure durations to tune surface energy, modify wettability, or prepare substrates for further processing. Simultaneously, the integrated OES system captures spectral data from the plasma plume, providing insight into the presence and stability of key species (e.g., Ar I, N₂, NO). This dual-control and diagnostics approach offers both treatment precision and in situ monitoring—critical for developing repeatable protocols in research and fabrication environments.
4. Accomplishments
- Integrated plasma jet with a 3-axis 3D printer frame for motion-controlled surface treatment
- Developed a custom fiber optic mount for in-line OES diagnostics
- Captured emission spectra of argon and nitrogen plasmas over time
- Automated spectral acquisition for long treatment cycles
- Demonstrated programmable plasma scan paths across test substrates
- Built the foundation for correlating spectral data with surface outcomes
5. What’s next?
The next phase of this project focuses on characterizing how treatment speed, torch-substrate distance, and multi-pass strategies influence surface chemistry and morphology. With the motion control system in place, we’ll begin testing different pathing routines to optimize for uniformity, activation depth, and edge resolution.
We’ll continue using OES to monitor plasma consistency, and supplement those measurements with electrical diagnostics using a double-tip Langmuir probe to extract real-time data on plasma density and electron temperature. Our ultimate goal is to build a data-informed treatment protocol that maximizes the functionality of optical and biosensor surfaces—especially those used in our parallel sensor development projects.
