Flex Sensor - 2.2"

Specifications

• Sensor Technology: Carbon Resistive Ink on Flexible Substrate
• Active Sensing Length: 2.2 inches (55.37mm)
• Total Physical Length: ~2.9 inches (73.66mm)
• Nominal Resistance (Flat): 25K Ohms (±30%)
• Nominal Resistance (90° Bend): ~60K - 125K Ohms (Varies by bend radius)
• Power Rating: 0.1 Watts Continuous; 0.5 Watt Peak
• Operating Temperature: -35°C to +80°C
• Life Cycle: >1 Million Flex Cycles
• Connector Pitch: Standard 2.54mm (0.1") - Breadboard Compatible

Applications

• Virtual Reality (VR) Data Gloves: Mount on glove fingers to track hand gestures for controlling games or drones.
• Robotic Grippers: Provide "proprioception" (sense of self-movement) to robot claws so they know how wide they are open.
• Assistive Technology: Detect small muscle movements in patients for rehabilitation devices or communication aids.
• Interactive Art: Create musical instruments where pitch or volume changes based on how much you bend the interface.
• Impact Detection: Use as a bumper sensor; the more it bends upon impact, the stronger the detected collision.

Wiring & Safety

CRITICAL WARNING: The bottom 5mm of the sensor (near the pins) is mechanically fragile. DO NOT BEND this base area. Bending here will snap the internal connections. Only flex the striped sensing area.

• VCC: Connect one pin of the Flex Sensor to 5V (or 3.3V).
• Signal/GND: Connect the other pin to an Analog Input (A0) on your board AND to one leg of a static 10kΩ - 47kΩ Resistor.
• GND: Connect the other leg of the static resistor to Ground (GND).

Package Includes: 1 x Flex Sensor 2.2"

Frequently Asked Questions (FAQ)

• How does the flex sensor work?
  It acts as a variable resistor. The more you bend it, the higher the resistance becomes.
• Can I cut the flex sensor to shorten it?
  No. Cutting the sensor breaks the conductive ink loop and destroys the device permanently.
• What is the resistance when flat?
  Approximately 25kΩ, though this can vary by ±30% between batches.
• What is the resistance when bent 90 degrees?
  Typically between 60kΩ and 100kΩ.
• Does it matter which way I bend it?
  Yes. The ink is printed on one side. You should bend it away from the ink (text facing out usually) for best results.
• Can I use this with a Raspberry Pi?
  The Pi does not have analog pins. You will need an ADC (Analog-to-Digital Converter) chip like the MCP3008.
• Is the connector waterproof?
  No. The sensor surface is water-resistant, but the crimped pins are open to corrosion and shorts.
• What resistor value should I use for the divider?
  A 10kΩ is standard, but 47kΩ often gives a wider range of values for subtle bends.
• Why is my sensor reading unstable?
  Check that you aren't bending the fragile base, and ensure your pull-down resistor is grounded securely.
• Can I solder wires directly to the pins?
  Yes, but be extremely careful. Excessive heat will melt the plastic film. We recommend using a connector or shrinking tube.
• What is the life span?
  It is rated for over 1 million flex cycles if used within the bend radius specs.
• Can this sensor measure pressure?
  No, it measures bending. For pressure (squeezing), use a Force Sensitive Resistor (FSR).
• Is the output linear?
  It is roughly linear, but for high-precision applications, you should calibrate it in your code.
• What is the difference between 2.2" and 4.5" sizes?
  Only the length of the sensing area. The 4.5" allows for measuring larger bend radii.
• Can I use this for a power glove?
  Yes, the 2.2" size is the perfect length for an average adult finger.
• Does it need a library?
  No specific library is required; standard analogRead() works perfectly.
• What voltage does it need?
  It is a passive component, so it works on 3.3V, 5V, or any logic level your board uses.
• How do I mount this to a glove?
  Most users slide it inside a fabric tube or sew a small pocket onto the glove finger so it can slide freely as it bends.
• Will it break if bent too far?
  It can handle up to 180° bends, but sharp creases or kinking the film will damage it.
• Is this compatible with ESP32?
  Yes, since it is a resistive sensor, it works perfectly with the ESP32's ADC pins (use 3.3V VCC).