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Question:

Is projected capacitive technology reliable when used outdoors in a marine environment where it will be exposed to rain, saltwater spray, bright sunlight, etc? What are the likely points of failure?

Thanks,
Charlie, Marblehead, MA

Touch Guy's Response:

Hey Charlie:

This is a most appropriate question for national sock burning day because, as is the case with all good sailors, Touch Guy barbequed his socks and pledged to go shoe-to-skin all the way to the last blustery days of Fall. 

Ah, but back to your question…Until recently, resistive touch was the only technology that was appropriate for marine applications. It could be fully sealed so that salt water was not able to corrode the protective hard coat, trigger a false touch or become impaired by a layer of salt.

The big problem with resistive touch is that the internal reflections make the display difficult to view in bright sunlight. Typically this problem is overcome by using a very bright backlight, a sun shroud or an expensive sunlight readable filter.

Projected capacitive technology is now the best outdoor solution because it does not have internal reflections and when optically bonded to the display, provides optimal readability. Some projected capacitive electronics are confused by salt water on the sensor but others are totally unaffected with by it - Touch Guy can help with this critical ASIC (Application-specific Integrated Circuit) decision.  And, if your marine vessel happens to be an aircraft carrier, it is easy to incorporate EMI and night vision filters into the touch sensor.

Other than lowering the boom on the sensor, there are no points of failure, although cold weather sailors will find that projected capacitive technology will not work with thick gloves. It is also important to note that you will need to seal and add a conformal coat to the circuit board to prevent corrosion.

So Charlie, let’s be sock-less ‘til November and get that projected capacitive touch screen on deck!

Until next time, Touch Guy

Do you have a question for Touch Guy? Send him an e-mail at asktouchguy@touchintl.com.