Material Solutions for Auto Interiors and Cockpit Applications
Innovations in capacitive sensing, embedded electronics and 3D shapes and forms are taking automotive interiors and cockpit electronics applications into the future, introducing new ways to interact with vehicle input systems, along with greater comfort.
Polymer thick film materials from DuPont, including conductors, dielectrics and resistive materials, are key components in these innovations, offering new ways to use and incorporate electronics. For automotive interiors and cockpit electronics applications, embedding electronics enables new levels of seat comfort and safety and opens the door to unprecedented levels of creativity, allowing designers the freedom to explore capacitive sensing in 3D shapes and forms.
Embedded electronics/in-mold applications
Vehicle interior surfaces, human-machine interfaces and consoles are migrating away from traditional “flat and square” to more appealing 3D shapes and forms, incorporating capacitive sensing and switching. Stretchable silver conductors and dielectric barrier layers from DuPont are making it possible to merge capacitive sensing with 3D shapes and forms, increasing reliability and decreasing failure modes associated with individual mechanical switches or buttons.
DuPont inks are highly compatible with a wide variety of plastic surfaces, including polyester, polycarbonate and graphic inks, and can be effectively embedded within the part’s structure via thermo-forming and over-mold processes. This places the inks very close to the “class A” surface, delivering the optimum spatial resolution for the sensor element while keeping electromagnetic emissions to a minimum.
Self-limiting heater systems
Heated or climate-controlled seats are one of the most popular comfort and convenience packages offered in vehicles today. Unique positive thermal coefficient of resistance (PTC) carbon compositions from DuPont, coupled with high-conductivity polymer thick film (PTF) silver conductors, deliver the perfect self-limiting heater solution. The PTC carbon compositions generate resistive heat to a certain specific temperature – because of the molecular nature, the temperature will not rise above this threshold. The total thermal mass of the system is determined by the shape, size, number and distribution of each individual printed heater element. Because each single resistive element is self-limiting, once the equilibrium temperature is reached, heat is only applied where it’s necessary without complicated electronic controllers or feedback loops. Different temperature levels are possible via simplified selector switches and heater circuit layout.
Safety is always a priority when resistive heat systems are deployed. PTC-based heaters are inherently safe, due to the way they function at the molecular level. The heater elements/heater matt always fail-to-cold independent of the failure mode. PTC-based heater solutions have been featured in automotive applications since the 1980s, and are chosen for their safety and efficiency by leading auto manufacturers today.