Introduction: SurferBot

About: Account to share rapid-prototyped scientific devices used in the Harris Lab at Brown Engineering. Our hope is that our posts will serve as accessible launching points for your future applications and designs.…

Inspired by a survival mechanism initiated by the honeybee trapped on the surface of the water, the SurferBot is a small robot that self-propels on the fluid surface. This low-cost and easily assembled devices is created by combining a coin cell battery with a vibrating pager motor. The SurferBot is able to move thanks to forces arising from a wave-generated, unbalanced momentum flux.


Check out the paper here: https://doi.org/10.1088/1748-3190/ac78b6

Preprint available at: https://arxiv.org/abs/2203.15896

Check out the video summary here: https://www.youtube.com/watch?v=PQF6yGAs-TA

Supplies

Needed for each SurferBot:

  • 2 sizes of cut out acetate sheets for the SurferBot body (ai and eps files below)
  • 1 SurferBot housing with double sided tape on the bottom (stl and f3d files below)
  • 1 coin cell battery (R626 377 SR626 177 AG4 1.5V Alkaline Coin Button Cell Batteries)
  • 1 vibrating pager motor (10000rpm Self Adhesive Vibration Motor 10x2mm)

Other Supplies Needed:

  • 1 tub, any size will do, filled with water

(Optional) For a giveaway kit:

  • 1 information card with QR code (pdf file below)
  • 3" x 4" plastic bag

Acetate sheets were laser cut on Universal Laser System - Model 4.60 - 30W (Red: Power 50%, Green: Power 15%)

Step 1: Assemble the Electronics

Take the pager motor and press it into the larger divot in the SurferBot housing. Take the coin cell battery and press it into the smaller divot in the SurferBot housing.

Step 2: Assemble the SurferBot

Take the red plastic off of the double sided tape on the bottom of the SurferBot housing. Take the smaller cut out acetate boat, and place the SurferBot body along the scored rectangle in the center.

Step 3: Turn the SurferBot On

Use your fingernails to poke the wires of the motor into the tabs around the edge of the battery, ensuring that the wires are making contact with the battery faces. Make sure that the wires doesn't touch the same end of the battery, especially on the side with a smaller face area (the one in the photo where the red wire is touching), as this will cause the battery to short.


If done correctly, the SurferBot should start to vibrate!

Step 4: Place the SurferBot on the Water

Place the vibrating SurferBot on the water in your tub, making sure that the body remains dry with a clean contact line of water and no air bubbles underneath. Watch the SurferBot go!

Share a video of your surferbot moving with #surferbot!

Step 5: What's Your Next SurferBot?

The larger acetate sheet is there for you to discover what shapes you want your next SurferBot to be!


Some questions to start you thinking:

  • How does size affect SurferBot Motion?
  • How does placement of the housing affect SurferBot Motion?
  • How does boat shape affect SurferBot Motion?