Reliability is the number one issue for design engineers, so how do they deal with the problem of liquid ingress?

As the Internet of Things (IoT) evolves, the networks that provide the connectivity we rely on need to be able to provide an ‘always on’ digital ecosystem.

In order for these smart devices to continually feed information to each other they need resilience, and that needs to be guaranteed.

Predictions vary, but if Gartner’s proves accurate, then within a matter of a few years, IoT technology will be appearing in 95percent of the electronics found in new product designs.

The resilience of smarter communication technologies and the networks that support them will depend on how vulnerable and reliable the devices and components that make them up are. If any of the links in that network are physically compromised, then the impact could be serious.

If individual nodes or smart phones are damaged, then data can’t be transmitted or received. So it’s critical that these devices are protected.

The main source of damage is physical damage, that’s a given, but liquid ingress also has a significant impact on the performance and connectivity of electronic devices.

Research published last year from IDC showed that 900,000 smartphones are damaged by liquid ingress every day around the world, and the impact of that damage on smartphones is estimated to be in excess of $96.7billion annually.

That’s an economic cost for handset manufacturers and network operators, as well consumers and insurance companies.

Nano coating solutions

One solution is a multi-chemistry hydrophobic nano coating solution to help maintain the reliability of devices.

A leading proponent of this coating technology is UK company, P2i, whose technology has been used to coat more than 250million electronic devices since it started working with smartphone manufacturers in 2011.

Based in Oxfordshire, its technology is deployed in factories across five different continents and is used to protect the smartphones of the leading phone manufacturers.

Beyond smartphones, this nano coating can be found on over 100 different consumer electronic devices, from tablets to accessories and headsets.

"Originally a university spin-out," explains Nick Rimmer, VP of Product Management at P2i, "our liquid repellent nano coating was developed by Professor Steven Coulson while at Durhan University. It was intended for military application protecting uniforms and equipment from possible chemical attack.

"We soon realised there were applications beyond defence where coating technology would be applicable. Initially, our focus was on clothing and footwear and it wasn’t until 2010 that we addressed the electronics sector and moved into protecting mobile phones. That market now accounts for 90percent of our business."

The market for nano coatings is certainly huge. Zion Market Research has predicted that worldwide demand for this technology is set to soar and could be worth $7bn by 2020.

According to Rimmer, "The benefit of using nano coatings is that gaskets or seals are no longer needed and that’s a real saving for manufacturers. The coating is applied through a low-pressure pulsed plasma deposition process that covers the device inside and out with a nano scale monomer which chemically bonds to its surface.

"We remove all the air from the process chamber using vacuum pumps so that the products are held at low pressure, then a radio frequency (RF) plasma activates the device’s surface, ensuring water and other contaminants are removed and free-radical sites are created."

The low pressure in the chamber means that the monomer can permeate into all areas of the device with the result being an ultra-thin layer of polymer that is just a few nanometers thin.

"That process enables us to make and break chemical bonds easily and gives us much better control of the actual coating process. As a result we can vary the thickness of the coating and its quality," Rimmer explains.

A significant benefit of this approach is that it provides much greater design freedom for the manufacturer.

"Whether we are adding a reassuring level of protection to expensive devices, or ensuring the cost-effectiveness for hundreds of thousands of low-cost sensors, these nano coatings ensure reliability. Crucially, our coating phase doesn’t require the manufacturer to change their product layout or production process."

According to Rimmer, P2i doesn’t sell its manufacturing equipment, but rather its income is derived from how many units are processed. "It’s easier and cheaper for the manufacturer and because we are paid per unit coated, we have to ensure that the equipment is running efficiently."

The process is integrated into an OEM’s existing manufacturing lines and the plasma chamber size is selected to suit the dimensions and volume of the products being manufactured.

In the coming years the prospect of millions of IoT devices being deployed means that they will be exposed to challenging weather conditions.

"By adding a hydrophobic nano coating it means that if a physical barrier is compromised, those devices will still be protected against corrosion and be able to operate efficiently," says Rimmer.

While the chemistry behind the coating is confidential, the technique is much like how water rolls off a ‘duck’s back’ according to Rimmer. "The coating enables water to roll off extremely quickly."

The company has experience of coating millions of smart phones and its coating process has no impact on component performance.

Some manufacturers don’t disclose their use of the process, but others actively promote it.

"Those that promote see it as a key differentiator for their product and mention the technology on their packaging," explains Rimmer.

"Every new customer will have a suite of tests to carry out on their products and components. So they will be checking to see whether our nano coating has an impact in terms of audio quality, the RF performance of antennas or whether the display functions are affected."

Looking to the future, P2i is working to bring new products to market with enhanced levels of protection.

"There are huge benefits that nano coating technologies can bring to the IoT and demand is booming," says Rimmer. "These are technologies that can add substantial value and reliability to a broad range of IoT devices, whether in the consumer or industrial space. Our hydrophobic nano coatings can ensure continuous connectivity throughout an entire lifecycle of a device."

Rimmer says that P2i will be looking to expand into markets such as agriculture, automotive and smart cities, as it plans to build on its experience in the electronics and military markets.

"We want to move to the component level and this is a response to the needs of the IoT. For example, in the automotive space it isn’t going to be practical to support the whole product or finished device – instead we’ll be targeting specific components, those that are considered critical to device performance. Our focus will be on stopping corrosion and we won’t need to supply ‘invisible coatings’ for devices that might be placed in the field, for example 5G base stations."

P2i is continuing to invest in research and development. "We are looking to develop new anti-stain, anti-fingerprint, anti-scratch, anti-microbial and protein resistant functional nano coatings," says Rimmmer. "We want to add new functionalities to a wider range of products, but, as always, our focus will be the reliability and performance of the coated devices and components."