Low power consumption and small battery size make it suitable for wearable products.

STMicroelectronics and USound, a fast-growing innovative audio company, are introducing silicon-based micro speakers as the first result of their technology collaboration announced last year.Engineering samples have now been delivered to key customers, and a formal demonstration is scheduled for CES 2018 in Las Vegas, USA.

Weighing less than half the weight of conventional speakers, these ultra-small speakers have been applied to wearable products such as earphones, over-the-ear headphones, and augmented/virtual reality (AR/VR) headgear. Their extremely low power consumption allows for further weight and size reductions by reducing battery size. Unlike conventional speakers, they also generate minimal heat.

MEMS technology has been applied to the capabilities of smartphones and wearable products. High-performance silicon-chip-based MEMS motion sensors, pressure sensors, and microphones are key to enabling functions frequently utilized by mobile users in their daily lives, such as context recognition, navigation, and tracking.

As advances in MEMS extend to speakers, audio subsystem designs are becoming more compact and power-efficient, enabling the development of innovative features such as 3D sound. Yole Développement, a MEMS industry market research firm, currently values the microspeaker market at approximately $8.7 billion and expects MEMS manufacturers to gain market share with silicon-based devices.

“This project’s success is a result of combining USound’s outstanding design expertise with ST’s extensive investment in MEMS expertise and processes, including our thin-film piezo technology, PεTra (Piezo-electric Transducer),” said Anton Hofmeister, Vice President and General Manager of ST’s MEMS Microactuator Division. “We are leading the commercialization of MEMS micro-speakers by leveraging the benefits of piezo-actuation to deliver solutions that deliver even greater miniaturization, efficiency, and performance.”

“We have brought ST’s product development expertise and manufacturing capabilities to realize our concept of a leading-edge product for consumer market opportunities,” said Ferruccio Bottoni, CEO of USound. “These compact speakers will not only change the design of audio and acoustic products, but also create new opportunities for the development of creative audio features.”

During CES 2018, Yoosound invited customers to ST's private suite to showcase prototype AR/VR glasses featuring multiple MEMS speakers on each side. When small audio systems are implemented in wearable products such as glasses, they face significant constraints in terms of space, weight, and power. However, the demonstration will demonstrate that the speaker's ultra-thin form factor, light weight, and excellent sound quality can be used to provide advanced features such as beamforming for personal audio and an excellent user experience.