Hot Hands
November 2018
Description
Hot Hands is a pair of gloves that warm up when you make a fist, press your hands together, or hold somebody’s hand. The main components are conductive pressure sensing fabric, conducting warming fabric, hand-sewn fleece lining, and a store-bought outer layer. The Eeontex Pressure Sensing Fabric is our sensor, which triggers a current to run through the Thermionyx Non-Woven Warming Fabric.
Material Creation
Fleece fabric used to create inner glove (for comfort and added warmth)
Conductive fabric on either side of pressure sensing fabric
→ pressure sensor
Kapton tape wrapped around warming fabric
→ insulation
Warming fabric sewn onto inside of the glove, pressure sensing fabric sewn onto outside of the glove
Technical Creation
Bending the wires through the pins left the circuit sensitive to movement, which was not ideal for something that would be worn
Solution: Solder the wires together to bypass the breadboard
Challenge: Soldering sometimes short-circuited the Arduino nano
Soldering also meant we had less to stuff inside the glove, as we could leave out the bulky breadboard
The warming fabric we used required a lot of power, meaning we had to find a an adequate power source without making the gloves too bulky or heavy
Instructables (by dannugeman):
Arduino Powered Heated Glove Liners
An important difference between our project and dannugeman's is the material used to heat the glove. While we used Thermionyx Warming Fabric from Eeonyx, this project used copper wire. While copper wire is conductive, wires are less comfortable and more dangerous, considering they will be right against the skin. Electric blankets are another common product that involve heating a material to be placed against the body, and those often have specified shut-off times and warnings due to the wiring and electrical danger. Using a conductive heating fabric is a safer option, though more difficult to power.
Adafruit Blog (by Leslie Birch):
How to Make Tech Gloves that Keep You Warm
Birch used LilyPad instead of Arduino, due to its size and ability to incorporate into wearables. We had considered using LilyPad when researching smaller microcontrollers, but due to our familiarity with Arduino, and comparative lack of familiarity with other microcontrollers, we decided to go with the Arduino Nano over the LilyPad. Other than that, they also used conductive thread rather than wires to create a circuit, which is something we were advised to consider during the critique on Thursday. In future, we plan to follow that advice, as it will give our circuit more flexibility and durability.
Instructables (by Shenzhen):
The main difference from Shenzhen's project is the same as dannugeman's, namely, the use of wire in such close proximity to the skin. Also, the carbon tape doesn’t allow for the same even heating across a larger surface area the way the Thermionyx material does. It would be interesting to see how we could combine the two materials, as carbon tape may be more suitable for heating smaller surfaces such as fingers. Perhaps with the use of conductive thread, the danger of wires could be avoided as well.
Resources
Making Gloves – Instructables
Example of Insulation – Adafruit
Temperatures – Embedded Artistry, Electronics Cooling
Circuits for Heating Pads – Instructables, SparkFun
Using a Relay – Circuit Basics
Team Members
Melissa Roberts
Samantha Sylvester