To keep the delicate and super-small sensors on a future iPhone or Apple staying clean and working flawlessly, Apple is studying the use of heat and light to break down contaminants.
Apple has a regularly updated support page on how users can keep their devices clean, but it can only go so far. The very oil from our fingers can make some device sensors less effective, and these may be inaccessible to users.
In a pair of related patent applications, Apple describes methods for allowing certain types of sensors on an Apple or iPhone to use their own cleaning system. They could deploy ozone, generated by ultraviolet light, to repel or even erode and break down “unwanted organic compounds” inside the device.
“Many mobile electronic devices are equipped with sensors and transducers that allow the devices to perform far more functionality than communications,” explains an application titled “Removal of Organic Contamination by Ozone Oxidation for Integration of environmental sensors ”.
A nearly identical application, focused on the UV side of the problem, says the exact same thing. They both go on to list how “measuring heart rate, blood pressure, and blood oxygen levels are just some of the many applications” such devices can use.
“In addition, smart mobile communication devices (eg smartphones and smartes) can be equipped with environmental sensors, such as pressure sensors, humidity sensors and gas sensors,” they continue. Apple has already studied the possibility of adding a sensor to iPhones that will detect toxic gases.
The problem with that and all of these sensors, especially if they have to be exposed to air, is that the air contains a lot of other things. “[Consequently] these devices are prone to the accumulation of organic residues, such as skin oils, dirt, body hair, etc. ”
“Such build-ups can contaminate the device case and / or the sensor packaging, which can produce interference signals and lead to increased sensor errors over an extended period of time,” Apple says.
“For example, miniature gas sensors rely on the diffusion of gas into the body of the device to detect an ambient gas and to infer the concentration of ambient gas,” continues Apple. “However, human skin lipids produce squalene, an oily organic compound that can adhere to the surface of the housing and / or the packaging of the sensor. Squalene reacts strongly with oxidizing gases (eg, ozone and nitrogen oxides), which could significantly increase the errors of these sensors. ”
Applications go on to mention how “conventional methods can use a physical mesh … to prevent the build-up of dust or larger ps”, but that this “may not be effective”. Another idea is to use the air flow, to have a fan blowing on the device. “[However this] The system may not be ideal for mobile devices, given the size, power and noise impacts. ”
Instead, Apple offers a system “to break down organic contaminants inside the product case or near the sensor packaging, to restore the clean environment necessary for the accuracy of the built-in environmental sensors.” And this system can be “using ultraviolet (UV) light to illuminate contaminants”.
“Ultraviolet rays can trigger a photo-oxidation process, which breaks down squalene,” says Apple. “Upon reaction with UV light, squalene, illustrated by its chemical formula, is broken down into three byproducts … which may not be harmful to environmental sensors.”
Detail of patents showing how ultraviolet light can be deployed in a small device
There are these two almost identical patent applications because they attempt to solve the same problem and do so with overlapping methods. Oxidation of ozone can break down some contaminants, but, for example, “[squalene] reacts strongly with oxidizing gases (eg ozone and nitrogen oxides), which could greatly increase the errors of these sensors. ”
UV light may therefore be the best option for breaking down contaminants, but UV light generates ozone. Thus, the two patent applications overlap because they detail the means to generate, control and use both UV and ozone in small devices.
Between them, the two patent applications are credited to a total of four inventors. They include Ashwin Balasubramanian, who was recently listed on a patent for iPhones to function as emergency beacons even when they are out of range of cellular service.