This is one of our favorite sensors! Originally designed as a low-cost physical interface for robotics, this simple pressure and flex sensor has found its way into an wide variety of projects!
Our sensor uses velostat, a piezoelectric material that changes resistance based on pressure, and copper tape sandwiched between two pieces of cardstock. Using this basic design, you can create different shapes and sizes to fit your specific needs. Long, narrow pressure sensors are great as finger flex sensors, while square pads are better for detecting and measuring changes in relative pressure.
Here is a quick overview on how to build the pressure sensor:
Attach two pieces of copper tape to the cardstock as shown, then connect two jumper wires to the copper tape.
Insert two pieces of velostat between the copper tape.
Fold the cardstock closed, use some tape to keep all the pieces inside, and you're all done!
Once you have built your sensor, connect it to Arduino, micro:bit, or another microcontroller that can print data to the serial monitor. Then write a simple program to read the analog value of the sensor and print it to serial (or use ours included in the next step!). Finally, open Excel and enable Data Streamer to get real-time pressure and flexion data!
Full build instructions for the sensor and a custom Excel workbook can be found here: https://www.microsoft.com/en-us/education/hackingstem/pressuresensor
Please reach out to us if you have any questions. Once it's up and running, we would love to see your creations and applications with this sensor, so please share away!