As we have become more dependent upon electronic technology for myriad applications in both consumer and commercial markets, their reliability and availability have become more critical. Harsh environments can lead to fogging or freezing, necessitating some means of heating, in some case immediately. The applications can range from display glass to a windshield to a headlight lens.
A transparent electric heating film is typically constructed by "sandwiching" a conductive material between layers of glass or clear plastic, traditionally polycarbonate or acrylic. The challenge here is deploying a conductive material that has both sufficient conductivity AND transparency. Patterns or opaque layers affect visual performance, while insufficient conductivity limits heating speed and range. CHASM's AgeNT TCF material is available at <10 ohms/square with greater than 90% visible light transparency, ideal for applications in avionics, transportation electronics, kiosks and more.
An automotive systems design firm was requested by a client to design a heater to keep headlight lenses clear of fog and ice, to prevent disruption of lighting and collision avoidance sensors. This presented a number of challenges:
Designing a heater with sufficient current density to perform at the automotive standard of -40°
Finding a transparent conductive material that could be molded or thermoformed
Finding a material transparent enough to prevent performance degradation of the sensors and lighting
CHASM's AgeNT-10 proved to be both conductive and transparent enough, resulting in a heater design that:
Met the heater spec for current density and warming time
Had a sensor that could be produced cost-effectively in volume
Can be produced using standard screen-printing technology
Can be produced cost-effectively