Sonexos raises CHF 5 million to bring plasma-based noise reduction to home appliances

Sonexos, a deep tech company based in Lausanne, has raised CHF 5 million in a Pre-Series A round led by Valquest Partners with Bosch Ventures, to industrialize its Plasmacoustic Metalayer, a thin plasma layer that absorbs low-frequency noise.

Sonexos has raised CHF 5 million in new equity financing in a Pre-Series A round led by Valquest Partners. Robert Bosch Venture Capital (Bosch Ventures) also participated, along with industry angels and private investors. Fadi Noureddine, founder and managing partner of Valquest Partners, joins the Sonexos board. The funds will help move the company from engineered prototypes to qualified industrial products, including paid prototype-integration programs with appliance and HVAC manufacturers. The most advanced programs target series production in early 2028.

A plasma layer that absorbs sound

Sonexos’ patented Plasmacoustic Metalayer uses a software-controlled plasma layer to absorb low-frequency sound at a surface. It is thin and light, and has no moving parts. Its core technology is licensed from EPFL. Under specific test conditions, prototypes reached noise reductions of up to 20 dB in ventilation systems and 16 dB in domestic appliances. Mark Donaldson, founder and CEO, who has about three decades of experience in active noise control and previously founded SoundChip, says engineers have always had to trade space and weight for silence, and that the technology removes this trade-off.

Industrial partners and data-center cooling

Sonexos works with STMicroelectronics through its ST for Startups program, with Roj, a subsidiary of the Vandewiele Group, for manufacturing, and with SIT on data-center fans, the first member of the Sonexos Certified Fan Partner Program. A second opportunity, the Plasmapanel Radial Active Silencer, targets data-center cooling fans, and a first working demonstrator is planned for CES 2027.