Internship: Simulation of plasma generation in varying gas compositions for trace biomarker sensing

Only for NL residents - No Visa support

Motivation: At RespiQ, we envision a novel and industry-standard gas sensing device, which can detect a wide variety of target biomarkers (e.g. Hydrogen, alkanes, cycloalkanes, cyclo-ketones, aromatic hydrocarbons), thereby eliminating the need for any chemical functionalization for a specific biomarker. With this, we aim for co-optimization of portability, sensitivity, time-to-diagnoses, and specificity, to develop a commercial solution for a healthier mankind.

Your expertise and contributions will help advance the company's mission of revolutionizing respiratory healthcare!.

Objective: A 6–12 month internship in partial or full compliance with an MSc thesis.

Scientific summary: In this assignment, we offer the candidate an opportunity to apply their knowledge in the fundamentals of plasma physics. At RespiQ, we conduct experiments on plasma generation and measuring the emergent OES from different gas mixtures in a matrix of air (N₂+O₂). We intend to conduct a numerical study of important plasma parameters as a function of the device operation parameters. The objective is to develop a knowledge base using theory and simulations that outlines the influence of varying device parameters on the plasma density and consequently on the relative intensities of light emission at wavelengths specific to the target molecule or radical (e.g. N, O, CH, H, C2 etc.).

Responsibilities:

1. Gain a solid understanding of the key components of the experimental plasma-based gas sensing device at RespiQ.

2. Propose a simple functional cross-section that embodies the key device parameters (e.g. electrode dimensions, electrode gap, gas composition, gas pressure, bias voltage)

3. Build a simulation deck in COMSOL Multiphysics to compute the spatial distribution of electric field, electron temperature, and plasma density, as a function of the device variables: gas molecule, concentration, DC voltage, pressure, and electrode dimensions.

4. Use the simulation results to calculate estimates of relative strengths of optical emission spectral lines, corresponding to known electronic transitions in the atom/molecule of the gas.

5. Provide estimates of limit of detection (LoD), and sensitivity to detect a given gas in the simulated device, by performing tolerance analysis against each device parameter.

Deliverables:

1. Literature survey: identify key and relevant optical emission lines from gases of interest and summarize the physics-based parameters necessary to compare the plasma density and emission intensities.

2. A representative plasma discharge cross-section for performing simulations.

3. Datasets (output variables): profiles of electric field, electron temperature, and plasma density, relative spectral line intensities for key plasma species.

4. Tolerance/sensitivity analysis of output variables against varying input parameters: pressure, gas ID, concentration (in case of a mixture), electrode dimensions, electrode gap, DC voltage.

5. A final internship report containing the above results.

Desired skills:

1. Background in theoretical plasma physics and atomic/molecular emission spectroscopy.

2. Interest and experience in finite element simulations. Prior experience in COMSOL Multiphysics via courses or assignments is highly appreciated.

3. Understanding of basic concepts in sensing e.g. signal-to-noise ratio, LoD, and sensitivity.

4. Background and interest in geometrical optics, and simple data analyses in Python or MATLAB.

VISA: Sponsorship is not possible

Stipend: Minimum salary

Job Location: Leiden, the Netherlands. Remote is possible up to 80%