Sonexos Raises $6.1M to Bring Plasma-Based Noise Control to Data Centers and Appliances

Lausanne-based Sonexos has raised CHF 5 million (about $6.1 million, or €5.4 million) in new equity financing led by Valquest Partners, EU-Startups reports. Robert Bosch Venture Capital (Bosch Ventures), industry angels and private investors also participated.

Fadi Noureddine, founder and managing partner of Valquest Partners, has joined the Sonexos board.

Solving the Low-Frequency Problem

Founded in 2022, Sonexos develops solid-state acoustic technology for low-frequency noise, the range where passive materials and speaker-based active noise cancellation fall short. The company holds an exclusive licence from EPFL for foundational plasmacoustic patents in its field of use.

Its patented Plasmacoustic Metalayer is a software-controlled plasma layer that absorbs sound at a surface, with no moving parts. The Plasmapanel, a sealed, inert-gas-filled module, absorbs sound from 30 Hz to 1,500 Hz and reportedly needs less than a fifth of the space and weight of passive silencers with similar low-frequency performance. In prototype testing, the company reports up to 20 dB of reduction in ventilation systems and 16 dB in domestic appliances.

Founder and CEO Mark Donaldson previously built active noise control companies, including SoundChip, which was acquired by DSP Group, now part of Synaptics.

Data Centers, HVAC and Beyond

Target applications include domestic appliances, HVAC, industrial and infrastructure equipment, automotive, and AI data-centre cooling, where reduced fan noise could ease community concerns and night-time noise limits.

Sonexos is working with Euronext Milan-listed SIT to integrate its technology into fan platforms, with a working demonstrator planned for CES 2027. Vandewiele Group, through its subsidiary Roj, provides a route to series manufacturing, and STMicroelectronics is supporting development of low-power, low-cost electronics.

Use of Funds

The capital will go toward industrialising the core platform; customer integration, reliability testing, qualification and regulatory compliance; expanding engineering and applications teams in Switzerland and internationally; and broader international IP protection.

"Engineers have always had to trade space and weight for silence," Donaldson said.

Source

EU-Startups — "Lausanne's Sonexos raises €5.4 million to tackle low-frequency noise from fans, compressors and even data centres"