Wireless Seat Heating Pad with Health & Wellness Benefits
Below is early circuit design concept for Automotive Printed Circuit developed by Dupont based on Application feature wants presented by Design HMI. Printed Heater are more efficient and flexible than the standard wire heater and are designed to deliver minimum 30% power efficiency – ideal for the Orthopedic Seat Designs.
Below is concept design developed by DYCOTEC.
Key Features:
- Fast time to heat < 3.5 minutes from -20C to 40C
- 10,000 mAh rechargeable battery.
- Bluetooth Connectivity for Hi/Med/Lo/Off settings
- All control through smart phone.
- Smart USB C Class Battery Charging Port.
- Occupant Sensing to reduce battery wastage
- Optional Accessory Cup Holder
- Anti-Microbial Coating to kill germs.
- Encapsulant Circuits for additional protection
- One (1) heating element per pad.
- Cell phone holder complete with USB charging port.
- Each pad with battery – 4 hours run time
- Lightweight foam
- Water Resistant heating circuits.
- Fire retardant materials
- Phase Change Material integrated for Comfort.
Target is to use Printed Heaters on Textile. Looking back at the heat sink analogy we notice that one way to lower thermal resistance is to increase the size, specifically the area of the heat sink. Even if our wire has a sufficient wattage the small cross-sectional size can increase thermal resistance and reduce efficiency. If the wire shape was changed from round to thin and flat (more like a heat sink) then thermal resistance could be greatly reduced. This thin flat profile gives printed heating elements a great advantage over the small round wire shape.
Another negative effect of the round wire is the non-conformal profile it has and thus heat path of a wire does not tell the whole story.
Wire heater are where the wire does not touch the foam. The thermal path of this area could be described as through the air then open cell foam and the leather to reach the surface. Three thermal resistances must be used to describe the heat path for this portion of the heater reducing the efficiency even further.
Printed heater heaters lay flat and have a profile that is highly conformal. It may seem hard to understand why a printed heater using the same input power could give better results than a wire heater, but when the model is considered in terms of thermal resistance the advantages become clear.
A few advantages and details:
Conformal coating of ink in the fabric for protection against dust, moisture and humidity, mold and mildew, extreme temperatures, particulate contamination and mechanical stress.
The nonconformal wire sits on top of the foam creating points in which the wire does not touch the surface and the heat must travel through air, then open cell foam then the leather to reach the surface. Heating element lays flat on the textile surface and creates a flat, highly conformal heating element.
The small cross-sectional size of the wire can increase thermal resistance and reduce efficiency. Heating element has a thin, flat profile which reduces thermal resistance and increases efficiency, uniformly spreading the heat across the surface.
For more information on application details contact designhmi@gmail.com
