[English]

Feasibility of Cymatics to Sort Spacecraft Soil Samples

(supervisor: Tony Cook)

Nature of project: experimental, data analysis

Available to full-time physicists or joint students.

Project description and methodology

On future sample return missions to Mars or the Moon, the mass of the material to return will have to be very small due to fuel constraints. It is therefore essential to be able to sort through soil samples to find materials of specific compositions and physical properties. These can be examined individually using a microscope and robotic tweezers, however this is very time consuming.

Cymatics is a technique whereby particles that are placed on a vibrating surface become redistributed in resonance minima or troughs. However not all the particles can occupy the same minimum position and so there can be some possible mass (or other physical characteristic) distribution of particles across the width, length and height above these resonance troughs.

By adding other properties to the system, such as different surfaces (roughness, elasticity, slopes), magnetic fields, it maybe possible to sort particles more thoroughly by shape, size, mass, magnetic properties, etc. Could such a system be used to sift through martian or lunar soil to help better select interesting samples to return to Earth? This project will seek to test out this idea.

A successful project will develop beyond the above in one/some of the following directions:
1) Demonstrate vibration patterns at different frequencies on a vibrating plate and examine particle size distribution (utilizing same composition particles) using a USB microscope, once the vibrations are switched off.

2) Experiment adding different surfaces (e.g. paint, varnish, rubber adhesive (dried)) to the plate and see what effect this has on the distribution of particles. Again use the same composition of particles, but again a variety of sizes.

3) Try using different gradients/roughness textures on the vibrating surface - possibly utilizing a 3D printer to manufacture this? Again use the same composition of particles, but again a variety of sizes.

4) Experiment with separating out a wide variety of particles e.g. iron filings, sand, flour, chalk dust, etc. But this time also use magnets to see how easy it is to trap iron particles on a vibrating plate.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: Try placing a stationary transparent plastic plate above the main plate to see if you can trap charged particles which have become charged through collisions on this 2nd plate.

Initial literature for students:

  1. http://www.rmcybernetics.com/projects/DIY_Devices/homemade_cymatics_display.htm
  2. Hans, J., (2002) Cymatics: A Study of Wave Phenomena & Vibration, published by Macromedia (312 pages)
  3. Madsen, M.B. et al. (1999) The magnetic properties experiments on Mars Pathfinder, Journal of Geophysical Research, Vol.104(E4)
  4. Chen, P. et al. (2015) Bio-Tunable Acoustic Node Assembly of Organoids, Adv. Healthc Mater. 4(13), p1937-1943.

Novelty, degree of difficulty and amount of assistance required

This is a fairly new technique and would be ideal for students interested in materials, or students with an interest in possible future space instruments.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Plan what equipment is needed and what experimets to doend of November
Source out materials to use, and plan any 3D printed plates neededChristmas
Demonstrate cymatic patterns and explore effects of different surfacesend of February
Experiment with different surface roughnesses and the separation of different particlesmid-March

Students taking this project will have to submit a full risk assessment form