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MicroSound

MEMS for loudspeakers

Due to its versatile mechanical and electrical properties, silicon has taken over the microelectronic and micromechanical worlds. Thanks to CMOS (Complementary Metal Oxide Semiconductor) and MEMS (Micro ElectroMechnical Systems) technologies yielded by this material, electronic devices are able to interact with our surroundings. This combination has created product categories such as smartphones and wearables, which would have belonged to science-fiction thirty years ago.

Still rely on one outdated principle for a critical function. Having originally been patented in 1877, the electrodynamic speaker is a holdover from the 19th century still surviving in our 21st century products. Being one of the only two smartphone functions not having transitioned to solid-state technology, it is responsible for the lacklustre audio performance ubiquitously decried by users. USound has developed its Microsound MEMS platform to address that issue, and bring back a positive audio experience to the mobile world.


Principle

anim piezo cantilever

 

USound’s base technology relies on piezoelectricity. Crystals exhibiting this characteristics, such as PZT (lead zirconate titanate), extend or shrink when an electric field is applied across its electrodes.

anim mems model

 

Using multiple cantilevers creates a translation, pushing a piston up and down. This replaces the traditional coil moving in a magnetic field as found in conventional speakers.

anim full model

 

Finally, mounting a membrane and a plate closes the acoustic shortcut and increase the effective area, thus enabling the sound generation.


Advantages

MEMS technology enables the repeatable production of intelligent miniaturised devices.
This feature combination opens the door for new use cases.

 

- Size

With its powerful and efficient piezo-actuators, MEMS speakers can be as thin as 1 mm, be shrunk to a footprint as small as 3*3 mm. Additionally, various electronic elements, such as amplifiers, can be directly embedded in the substrate, to achieve further system-level space reductions.

 

- Intelligence

Power efficiency, no heat generation
Fast time response – accurate and clear sound
Extended bandwidth for HD audio and ultrasound applications
Lightweight, low vibration
Simultaneous microphone functionality

- Reliability

Shock resistant
Tight manufacturing tolerances
Self-testing
Adaptive to working environment
Peak and overdrive control

 

- Manufacturing

Precision of semiconductor processes
Volume scalability
High yield of semiconductor fabs


Innovation

Bringing the audio-consumer experience to the next level.
USound is developing next-generation acoustic applications.

 

Compact sound generation

Thanks to advanced-packaging technologies, such as embedded or 3D-SiP solutions, USound can offer fully-integrated products, combining amplification, with the possibility to add DSP and other functions.

Integration with smart microphones

With the rise of voice functionalities, sound generation needs pairing with sound sensing. MEMS microphones are already ubiquitous, with billions produced each year. Using the same technology for the speakers enables integration of functions in one package, thereby opening for new applications.

Speaker arrays

As the MEMS speakers are intrinsically matched through batch processing, creation and control of multi-speaker arrays is extremely simplified, opening the field for directional sound and other similar applications.

3D audio

Due to the small transducer size, multiple drivers can be integrated in very-small volumes. This would enable the creation of hardware-based 3D-audio systems.