We decided to create a brand new robot totally different from our midterm one: a jellyfish in the air.
From this video we found that actually jellyfish moves by propelling water out its body, instead of commonly thought by moving those tentacles.
We felt that it may sound more fascinating to make a jellyfish in the air, so we can let it float around us and follow us where ever we go.
The project contains 5 parts:
1. structure
We decided to make jellyfish-like double-layer membrane filled with helium to make it able to maintain its position in the sky without falling down. (It is mainly to save power, else the propulsion part will have to keep running)
2. control
We decided to use microbit with robotbit as before. In addition, we need a voltage transformer this time to support our propulsion part.
3. movement
The most exciting case, also the most difficult one, is that we will design, test and make a special Electroactive Polymers (EAPs). It is a material that will shrink sharply when receiving electrical current or field. So, it can act as artificial muscle to simulate in inhalation and exhalation (propulsion) of jellyfish.
After researching, we discovered a way to make it: using PDMS membrane and Graphene.
However, as EAPs material is an advanced material science, there are chances that the result might be not as we expected. So I prepared a backup plan: just using helicopter fans to propel it.
4. power
Currently we have 3 options:
a. use battery (most simple, but might be heavy and not good looking for the jellyfish)
b. wireless power (requires some extra knowledges technologies and experiments)
c. solar power board (expensive)
5. detailed modification
Mainly decoration, testing, programming and changing argument in software.
Sources:
Yoseph Bar-Cohen. ELECTROACTIVE POLYMERS AS ARTIFICIAL MUSCLES – CAPABILITIES, POTENTIALS AND CHALLENGE. JPL/Caltech. 4800 Oak Grove Drive, Pasadena. CA 91 109-8099 Phone 8 18-354-2610. web: https://trs.jpl.nasa.gov/bitstream/handle/2014/18826/99-2121.pdf?sequence=1
Adelyne Fannir et al. Linear Artificial Muscle Based on Ionic Electroactive Polymer: A Rational Design for OpenāAir and Vacuum Actuation. https://onlinelibrary.wiley.com/doi/full/10.1002/admt.201800519
Steven Ashley. Artificial Muscles. Scientific American. October 1, 2003. https://www.scientificamerican.com/article/artificial-muscles/
IAD ZHdK, Electroactive Polymers Part 1: Shower Hose Stretching Mechanism Video Tutorial, Zurich University of the Arts (ZHdK), Interaction Design Program,
All Five Oceans, How do Jellyfish Move ?, https://www.youtube.com/watch?v=qlgGsjw3LREs