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Going beyond water-resistance to waterproof smartphones

Published: 3 November 2016 - Sarah Mead

One of the most frustrating features, or lack of, in today’s smartphones is true waterproofing. While the Samsung Galaxy S7 and the Sony Experia X both claim to be water-resistant, they are not quite waterproof, as some reports suggest.

Credit is certainly due to Samsung and Sony, who are clearly responding to the demands of consumers. According to a recent Redux survey, one in five consumers have damaged their device by dropping it in water or by spilling liquid on it. At the very least, both companies are attempting to reduce the number of returns from customers due to water damage —TSB Insurance revealed that customers make more claims due to water damage (23% of smartphone claims) than anything else.

The approach Samsung and Sony take to make their phones water-resistant is fairly similar. Both companies place seals around possible points of entry to the internals of the phones, including the power button, SIM tray and headphone jack. Both companies use glue and tape to hold the seals in place, with a mesh screen to protect the speaker grille that provides enough surface tension to deny water entry while allowing air to pass through for the speaker to work.

However, the problem with using seals, glue and tape is that these only protect the phone against immersion in fresh and cool water. What about using the phone in a swimming pool, which contains chlorine; or in salty seawater; or the bath, which contains hot soapy water? The corrosive elements in non-freshwater liquids can dry out and erode the seals and tape, rendering them less effective. Hot water can also soften the rubber gaskets. Therefore, current waterproofing methods are really only useful for protecting against one-off accidents rather than enabling devices to be used in regular contact with water. Also, few consumers will be willing to ‘risk’ their device by cleaning out the rubber seals should they expose it to one of these liquids by accident, which would leave corrosive residue behind.

Vents and rubber gaskets always run the risk of letting in ingress. No matter how durable manufacturers make them, time will eventually wear them away, which is why manufactures are looking for alternatives to improve waterproofing levels. Aftermarket sprays like Nanostate’s Flash Flood provide a durable coating to (supposedly) protect your device from moisture by forming a powerful barrier over the entire device — making it liquid and moisture resistant. Some companies are exploring ways to go a step further by nano-coating the internals of a device during the manufacturing process. So instead of the casing of the device being waterproofed, the individual components within the device would theoretically be water tolerant. However, the cost of this approach has so far proved to be a barrier to mass uptake by manufacturers.

So what else can manufacturers to do address the waterproofing challenge?

One way would be to create a totally sealed device — i.e. one that does not feature vents or grilles or any other points of entry to the phone, therefore removing the need for seals, gaskets and aftermarket sprays in the first place.

The most straightforward of these vents to resolve is the microphone. By manufacturing the microphone’s membrane and surrounding container out of a water-resistant material, this port can enjoy a watertight seal. The next step would be to replace headphone and power ports with a wireless alternative.

But that still leaves the speaker grille as a major point of potential ingress.

One solution, which could remove the need for a micro-speaker and grille altogether, is available through surface audio technology. Surface audio uses innovative bending-wave technology to turn the screen or rear panel of the phone into a high-quality loudspeaker.

This technology is available today, therefore manufacturers could take advantage of it in their designs now. The quality of sound from panel audio is also better, with greater loudness, stereo separation, naturalistic sound with good frequency range and low distortion. What’s more, the same technology can create high-fidelity haptic effects for the user, further differentiating the product.

The race to produce the world’s first properly waterproof smartphone is on.

By John Kavanagh, CCO, Redux

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