During summer, we all try to stay away as much as possible from excessive exposure to the sun that can cause heatstroke. Since it’s not possible to carry fans and air-conditioners (ACs) everywhere to cool ourselves, our bodies struggle to maintain an ideal body temperature.
To solve this problem, I have conceptualised a prototype of a small AC that uses a thermoelectric module based on the Peltier effect. The small AC can be worn on hands for absorbing heat from our skin and thereby cool our bodies.
The wearable device is also suitable for detecting the body pulse rate. The device absorbs the heat from our veins to cool down the flowing blood. That cool blood then passes through different parts of the body while another stream of blood flowing under the wearable device gets cooled. In this way, blood circulation occurs, resulting in body temperature regulation in a matter of a few seconds.
The wearable AC is not only useful in summer but also winter. By changing the polarity of the thermoelectric device, it will start to heat rather than cool our bodies.
So to create this exciting project, let’s start by collecting the following components.
Bill of Material
Designing
Here, the 3D design of our device consists of a body heat-regulating system and a battery. It has vents at the top to release hot air. You can modify the device and add sensors for measuring the body pulse rate.
To begin constructing the device, first, connect the thermoelectric module and battery to a small fan.

Next, assemble all components, including the fan inside the thermoelectric module such that it stays in direct contact with the skin for absorbing heat from the human body (see above figure).

For the device’s cover, use cardboard or a 3D printed material. You can also customise the design as required. Download the CAD file that will help to design the enclosure.
After designing, fix a leather belt, chain or any other comfortable band for wearing the device on your wrist.
What’s Next?
The wearable is ready for use now. To make it more innovative, you can modify it further. Here is an idea for making a body temperature regulating AC.
For this, you will need the following components.
- MAX3001 sensor
- Arduino Pro Mini
- MOSFET
- LM35 sensor
Connect the LM35 and MAX30100 with the Arduino Pro Mini pins. Then connect the MOSFET with the thermoelectric module and Arduino, and connect the whole circuit to the battery. Follow the circuit diagram given below.