Materials List: Create and Control a Popsicle Stick Finger Robot

Flex sensor and servo circuit materials:

  • computer, Windows or Mac
  • Arduino software; download from
  • SparkFun RedBoard or Arduino Uno microcontroller and programming cable; an Arduino Inventor’s Kit is recommended (some of its many components are the items listed below), such as for $99 at SparkFun
  • breadboards
  • 10k-ohm resistors
  • 180-degree servos; one comes with the Arduino Inventor’s Kit recommended above—the generic sub-micro size servo for $9 from SparkFun, or obtain higher-quality servos such as the Hitec HS-422 standard size for $10 from SparkFun
  • flex sensors; one comes with the Inventor’s Kit above—a 2.2-inch flex sensor for $8 from SparkFun
  • soldering iron, to prepare the flex sensors; see note below
  • solid core wire
  • shrink-wrap

Note: The flex sensor pins are not ideal for use with breadboards. So, in preparation for this activity, it is recommended that you solder two solid core wire leads that are at least 6-inches long onto the flex sensor. After soldering the solid core wire, apply shrink-wrap to the leads to protect the flex sensor during the activity.

A photograph shows a person’s hand with a flex sensor taped onto its index finger. Additional wires have been soldered on the flex sensor.
A flex sensor (with additional wires) taped onto a finger.
Copyright © 2017 Dan Godrick, ITL Program, College of Engineering and Applied Science, University of Colorado Boulder

Finger materials:

  • Popsicle sticks
  • string
  • elastic bands
  • glue
  • tape, to affix the flex sensor to the hand; encourage students to experiment with other methods—gloves, athletic wrap and stretch fit materials (such as these cool finger sleeves from JBM) work well!