One of these days we’ll have an iPhone that’s truly waterproof without having to add a third-party case. Apple is working on this, as evidenced by a newly granted patent (number 10,034,073) for a device having a “composite acoustic membrane.”
In the patent filing, Apple notes that devices such as an iPhone may be exposed to water, e.g., rain or water in a swimming pool. Porous membranes are used to protect electronic components within such electronic devices from particle or water ingress. Such membranes may also allow air exchange between an environment surrounding the electronic device and an enclosed volume within the electronic device.
Air exchange across the barrier may be important when ambient pressure swings, e.g., from changes in altitude, can impact the function of an electronic device and device components. For example, a pressure difference across the barrier may cause the barrier to stretch and become effectively stiffer, which may impact acoustic transparency in the case of microphone or speaker barriers, and could damage or break the barrier. Thus, in water resistant applications, porous barriers are typically used. Apple wants to take this to another level.
Here’s the summary of the invention: “An electronic device having a composite acoustic membrane to inhibit water ingress and to allow sound transmission, is disclosed. Embodiments include an electroacoustic transducer within an encased space of a casing, and a composite acoustic membrane between the electroacoustic transducer and an acoustic port in the casing. The acoustic membrane may include a nonporous region at least partly covering the acoustic port, and a porous region to vent the electroacoustic transducer volume to the encased space and/or to an environment surrounding the casing. Other embodiments are also described and claimed.”
Of course, Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.