Model of Prokaryotic Bacteria - DC Motor Flagellum

This project is for STEM students in Year 7 to learn about the structure of bacteria, how DC motors connect to electronic switches and batteries and practice some basic construction techniques using cardboard, tape, craft knives and soldering.

Here's what you'll need to make your own bacteria:

Materials = [Cardboard, Gaffer tape, Marker Pens, Bamboo Skewers, Wire]

Tools = [Screwdriver, Soldering Iron, Multimeter, Computer]

Electronic Components = [DC Motor, Wire, Switch, Batteries]

I used TinkerCAD as a drawing tool before I build, so I have a better idea of what I'm trying to make. I have created a 3D Model with AA batteries, motor and switch spread around the body of the bacteria, so the weight is evenly distributed. I have based the shape of the bacteria on the prokaryotic cell shown in the videos linked above.

I have use the Circuit Design part of TinkerCAD to check that the circuit works before I attempt to create it IRL.

1. I didn't want to buy anything for this project, so I decided to harvest some DC motors from an old useless computer. The DVD Drive yielded 3 different DC motors. I accidentally broke one of them straight away. Oops. I then connected wires to one of my batteries and tested the other two. The one that worked on 1.5 volts is the one I decided to use for this project.
2. The old DVD drive also gave me some nice lightweight insulated wires to use. I attached these to the batteries using gaffer tape, because I didn't have a battery clip at the time. If you can get a battery clip you can skip a lot of finicky mucking around.
3. Once I had wires attached to each battery, I soldered the circuit together in the same way as the TinkerCAD design from the previous step. When soldering little components I tape them down so they don't run away from me while I've got a soldering iron and solder in my hands.

1. I drew the shape of the bacteria onto some cardboard.
2. I cut the shape using a craft knife. Be careful kids. Use scissors if you aren't able to use a craft knife.
3. I had to improvise a bracket to hold the motor onto the body of the bacteria. This involved cutting a long cardboard strip and bending it around the body of the motor, and cutting a slot in the body of the bacteria.
4. I used gaffer tape to hold together all the parts.
5. I originally thought of using bambook skewers for legs, but these didn't work very well so I cut some wire from this old broken clothes hanger, which worked a lot better.