A fully 3D-printed sensor that feels every finger bend

OpenPrintSense

The key part of OpenPrintSense is a flex sensor printed entirely from filament. Bending the finger stretches the conductive track, its resistance rises – and a tiny microcontroller turns that into a percentage, live on your phone.

Explore the 3D model View on GitHub

Open source · MIT license

Build your own

Everything you need is on GitHub – print it, flash it, install the app.

  • CAD files – STEP and print-ready 3MF
  • Arduino firmware for the XIAO nRF52840
  • Android app with calibration and game
View on GitHub

Explore the model

Drag to rotate, scroll to zoom, click a part for details.

Loading 3D model …

How it works

  1. You bend your finger – the conductive filament stretches.

  2. Stretching increases the electrical resistance of the track.

  3. The microcontroller reads the change via its analog input.

  4. The calibrated value is sent to the app via Bluetooth Low Energy.

What you can do with it

A cheap, printable sensor that measures how far a joint bends opens up a lot of ideas:

VR & AR controllers

Natural finger input for grabbing and pointing in virtual worlds – a low-cost alternative to expensive data gloves.

Rehabilitation

Guided finger and joint exercises after an injury, surgery or a stroke – with live feedback and a game that keeps you motivated.

Range of motion

Measure objectively how far a joint can bend and track it over weeks, for example with arthritis or after an operation.

Robot & prosthetic hands

Mirror your finger movements onto a robot gripper or a prosthetic hand for intuitive remote control.

Sign language & gestures

With one sensor per finger and a little machine learning, hand signs and gestures can be recognised.

Music & MIDI

Turn finger bends into pitch bends, filter sweeps or drum hits – an expressive instrument controller you wear.

Accessibility

A small finger movement as a switch, mouse click or game input for people with limited mobility.

Sports & research

Record joint angles during training, ergonomic studies or motion capture – a larger print could also go around a knee or elbow.

Try the app

A simplified browser version of the Android app. No glove at hand? The slider simulates your finger.

Simulation only – the real app connects to the glove via Bluetooth.

🧤 SmartGlove
Not connected
Stretch 0%
Raw value: 0
Calibration Not calibrated

Put on the glove and start calibration

Min: 0 | Max: 1023

What you need

  • Seeed XIAO nRF52840 Sense – microcontroller with Bluetooth Low Energy
  • TPU 90A – flexible base
  • Recreus FilaFlex Conductive – the sensing element
  • 2 flat connectors 2.8 × 0.5 mm and two jumper wires
  • USB-C or 3.7 V LiPo plus a few wires and a pull-down resistor
  • Android phone (Android 8.0+) for the app
OpenPrintSense sensor on an extended finger Finger bent with the sensor, XIAO board on the back of the hand Close-up of the light-blue TPU base with the black conductive track