Take your wearables for a dive: these next-generation MEMS speakers withstand permanent submersion in water

USound, the Austrian company pioneering in MEMS audio technology has developed the next generation of MEMS speakers, surpassing market demands with its IPX8 water submersion resistance.

USound has been developing piezoelectric silicon MEMS speakers for over half a decade and has now introduced the second generation of speakers after having secured sizeable contracts with Chinese manufacturer 3nod Acoustiklink and other renowned tech brands in Asia and the USA.

“Thera”, the second generation of MEMS speakers, integrated into an off-the-shelf audio module including amplifier and passives, widens the possibilities for earphone designs. It can be implemented into the earbud, offering more space for other components such as battery and sensors. Due to its state-of-the-art MEMS audio technology, it reaches maximum excursion at the smallest thickness.

With the recently conducted IPX8 tests, the speakers not only excel in form factor, weight and SPL on a broad bandwidth but can also be safely submerged up to 3 metres for about 30 minutes. This opens new application possibilities for both personal and professional uses close to water or underwater.

CTO Andrea Rusconi Clerici sees TWS (true wireless earbuds) as one of the main use cases. “For TWS use, sports are an important theme. Headphones are being equipped with additional sensors, trackers, music storage, and AI coaching; and the fit and the IPX rating helps offer a greater variety of workouts, including swimming”, he states.

Adding microspeakers without the adequate IPX qualification can be a tedious challenge as the mechanical design and assembly process of earbuds have become increasingly complex. Providing the complete MEMS audio module as USound does allows manufacturers to save time, avoid additional costs and still provide high-end audio performance without having to develop and optimise the acoustic environment of the earbud.

Rusconi Clerici further says, “These results of the water-resistance tests are exceptionally good and better that anyone’s in the market. We know that many of our customers and other big players are highly interested and looking at IPX8 as top of the list for selling points for true wireless earphones.”

The speakers will be available with a diameter of 6mm or 10mm. USound is already sampling this version of MEMS speakers to top clients and will be available for mass production in 2021.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 858342.

Innovation in the audio industry

USound microspeakers not only improve existing audio systems with their signature crisp and clear audio but also enable diminishing the diameter and weight of the housing of any wearable or hearable due to the speakers’ reduced size.

As a result of MEMS batch processing and a fully automated manufacturing process, the part-to-part variation is the lowest in the audio industry. MEMS speakers comply with international reliability standards to ensure robustness and stable performance over the product lifetime.

Compared to other MEMS-based solutions available, USound MEMS speakers meet the market-demanded SPL requirements in the entire audio bandwidth and beyond, which enables not only sealed applications such as in-ear but also free-field and near-field applications such as wearables and ultrasound applications.