Designed to address the increasing demand for touch sensors, 3M Touch Systems Inc. has introduced its MicroTouch flex capacitive touch sensors in roll form. The polyester-based projected capacitive touch screen solution is suited for high-volume mobile display products, such as cell phones and PDAs, as well as other home appliances.
The sensors are manufactured using a unique roll-to-roll process by applying a variety of patent-pending indium tin oxide (ITO) patterns on lightweight polyester film (PET). According to the St. Paul, MN, U.S.–based company, the result is an incredibly thin, optically clear projected capacitive touch sensor available to device manufacturers in rolls containing up to 72,000 sensors, depending on size.
“This allows us to customize the pattern for a specific customer and produce high volume to meet customer demand,” explains Kelly Devin, business development manager for MicroTouch flex capacitive touch sensors. “Other touch sensor suppliers using PET tend to purchase precoated PET (unpatterned ITO), and then process the material to remove some of the ITO on the roll to produce the touch sensor pattern.”
Devin says that 3M’s ability to pattern the ITO in-house frees the company from the present supply constraints in the market for unpatterned ITO. “Supplying a touch sensor on a roll allows for automated manufacturing further in the supply chain, specifically when laminating the touch sensor to a decorative or protective lens,” she says. “Our ability to produce touch sensors on rolls means our customers can get the quantities they need when they need them.”
Because the sensors are film based, they can also be customized into different shapes and sizes, giving engineers more design flexibility. “The touch sensor can now move beyond the traditional square shape and be oval to provide a more aesthetic appearance to white-goods appliances like a washing machine,” Devin says. “It could also be used on cellular handsets that are moving toward more-rounded corners or oval shapes.”
The company says the sensors can be designed for touch applications ranging from simple button operation to full X, Y touch screen capabilities. According to Devin, applications for this product span the entire range of mobile handheld devices, including—but not limited to—MP3 players, personal navigation devices, digital cameras, high-end remote control devices, and ultramobile PCs. “The uses could certainly expand into white goods as well as into business devices like photocopiers,” she adds.
Various material thicknesses from 2 to 5 mil are available to meet compact design requirements. The components can also be optically laminated to a glass or polycarbonate lens for surface durability with touch sensitivity “projected” through the lens. The company says that by using hard-coated polyester, the sensors can work directly as lightweight touch screens for devices requiring a more economical and thinner touch profile.
|Suppliers mentioned in this article: