Build BOTS!
Make a Pencil Pressure Sensor!
Adapted from the book BOTS! from Nomad Press by author Kathy Ceceri
The Pencil Pressure Sensor makes the LED light dim or bright, depending on how hard you press on it!
Read the original paper!
Low-Cost Graphite on Paper Pressure Sensor for a Robot Gripper with a Trivial Fabrication Process
A pressure sensor made using the graphite from a pencil was attached to a Baxter robot. On the right is a Baxter robot used in research at RPI in 2014. The Baxter model has since been retired.
Supplies
Troubleshooting Tips
If your sensor doesn't work, check that:
all conductive material makes a good connection
the polarity of the LED matches the battery
the positive and negative sides of your circuit are not touching, which can make it short circuit
the pencil "switch" is closed
color in pencil "bridge" nice and dark, using the long strokes from side to side
penciled area lines up with the battery
To check whether the problem is with the penciled area, try connecting the two sides of the circuit with an extra piece of foil.
Pressure Sensors in BOTS!
Sensor Challenge — Design Your Own Robot Sensor
Try using a coin battery and one or more LEDs to design different kinds of robot sensors. This example from my book BOTS is a tilt sensor. Find the instructions below:
Page 71 in my book BOTS
Want More Great STEAM Projects?
Check out my book BOTS! from Nomad Press
Look for more free activities you can do at home on my Projects page