Fraunhofer subsidiary develops silicon micro loudspeaker

Arioso Systems, a spin-off company of the Fraunhofer Institute, is developing a micro in-ear loudspeaker made from 100% silicon based on Fraunhofer’s Nanoscopic Electrostatic Drive (NED) technology.

The silicon-based transducer does not use a conventional membrane, instead being installed inside the body of a silicon chip as a series of bending strips.

Electrostatic actuators, ‘nano E-drives’ are integrated inside 20 µm wide bending strips, becoming energised by vibrations from the audio signal voltage to become intelligible as sound.

The components can be integrated directly into the silicon chip, with the micro loudspeaker being designed for in-ear headphone or ‘hearable’ applications.

'Hearables' are wirelessly connected Internet device that allow features such as instant translation, pay functions and a variety of speech-based and internet services.

Speaking to Inavate, Jan Blochwitz-Nimoth, managing director, Arioso Systems explained: “In today’s modern headsets, like Apple AirPod Pros, you see that the most parts are chips and mounted on flexible printed circuit boards and just put inside the housing.

“Today’s speakers are roughly 10 millimetres in diameter and four to five millimetres thick. The volume that is covers inside this tiny device is very high and we aim to have it  go down to below fifty cubic millimetres. It's a very small chip and we save a lot of space and we save a lot of weight, allowing this extra space and weight availability to be used for batteries.”

Doing more with less weight in smaller environments is key to the development of ‘hearable’ technology as Blochwitz-Nimoth added: “People want headphones which are ultimately connected to the internet, you need more electronics and every component must be small and lightweight.”

“We still have to work on the performance of the technology, followed by long-term testing before we can hit the market with a product within the next four years. We aim to work with customers and have them contribute to our development."

Blochwitz-Nimoth closes: "Intrinsically, audio quality should be excellent; electrostatic loudspeakers are considered the ‘holy grail’ of loudspeakers and while electrostatic speakers can be expensive, from a high-fidelity standpoint they are exceptional. With our Chip based ideas we make this electrostatic approach feasible for In-Ear-Headphones and Hearable both technologically and price-wise.”

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