Soft Robot Out of Hot Glue Sticks




About: I am a University of Edinburgh electronics engineering student.

Here is an inspiration for you on how to make a soft robot in less than an hour!

Okay, it is not exactly soft you will argue, but it has some soft parts - the glue sticks! Not only they are soft, but they have a very important feature - they form the body of the robot and they act as springs. It is important to realise that their springy quality is used to drive the robot forward.

The robot is able to move because its tail has very little friction with the ground when moves in one direction and very high friction on the opposite direction. The tail is simply pulled forwards by the two ropes. Then they release, the springy quality of the glue sticks pushes the front forwards while the tail is stuck to the ground.

Check the video and you will see what I mean.

Step 1: Stuff You Need

The list is very simple:

  • Some thin nylon rope
  • Hot glue and sticks
  • Servo
  • Arduino (Uno or Mini or any other microcontroller that can drive a servo)
  • Battery

Step 2: Hardware Assembly and Software

Connect your servo to the microcontroller and power supply. I used two servos to give me more power on the ropes, but it is up to you and the actual servos you find. Then program the microcontroller to swing the servo backwards and forwards. Check the code attached.

Finally, put your robot together! Stick the servo in a box and feed the rope through it. Stick a glue stick to the box and bend it. Tie the end of the rope to the free stick end and that is it! Use my diagram as a reference, but feel free to experiment on your own. There are infinite number of solutions. Share them in your comments below.

The boxes that house the microcontroller, battery and the servo are 3D printed - not the cheapest way but it looks neat!

Step 3: Testing on Different Sirfaces

It is able to crawl over artificial grass, smooth plastic and rough terrain. I had to add spikes to the tail to make the friction greater on the grass terrain.

Step 4: Race!

It isn't rocket science, but it is cool!

Thanks for checking! Please vote for my instructable in the contests if you've found it inspirational!

Share your thoughts, comments and designs!

Hot Glue Challenge

Runner Up in the
Hot Glue Challenge



    • Arduino Contest 2019

      Arduino Contest 2019
    • Colors of the Rainbow Contest

      Colors of the Rainbow Contest
    • Classroom Science Contest

      Classroom Science Contest

    17 Discussions


    2 years ago

    Hi there, great!!

    I want to make one but what did you use for the 'soft spine'?


    3 years ago on Introduction

    hang on I forgot what I was gonna say and that's SUPER COOL! I'm big in robots ;3


    Reply 4 years ago on Introduction

    It must be possible by adding two extra servos. I imagine it like they will be changing the friction with the surface and make the robot steer.

    hertzgammaSlime Eel

    Reply 4 years ago on Introduction

    Thanks Slime! I did not even know what a nudibranch is but now I do ... haha it actually looks like one for real I think because of the orange spikes it has!


    4 years ago on Introduction

    This is so bisare and completely amazing! I can't keep from watching that video.