Sonexos SA, a Switzerland-based deeptech company developing solid-state active noise control technology, raised CHF 5 million (approximately $6.1 million or €5.4 million) in a Pre-Series A equity funding round.
The round was led by Valquest Partners, with participation from Robert Bosch Venture Capital GmbH (Bosch Ventures), industry angel investors and private investors. Fadi Noureddine, Founder and Managing Partner of Valquest Partners, joined Sonexos’ Board of Directors.
Founded in 2022 by Mark Donaldson, Sonexos is headquartered in Lausanne, Switzerland. The company develops plasma-based acoustic technology designed to reduce low-frequency noise generated by fans, compressors, motors and ventilation equipment.
Sonexos’ core technology, the Plasmacoustic Metalayer, uses an electronically controlled layer of plasma to absorb sound. Its Plasmapanel system integrates this technology into compact modules designed to provide noise reduction without the bulky materials or moving components associated with conventional acoustic treatments.
The technology targets applications in domestic appliances, heating, ventilation and air conditioning (HVAC) systems, industrial equipment and data centre cooling infrastructure.
The company is led by Founder and CEO Mark Donaldson, CTO Dr. Stanislav Sergeev and COO Andrea Onetti. Its underlying plasmacoustic technology originated from research at the Swiss Federal Institute of Technology Lausanne (EPFL), where Sergeev worked on plasma-based sound absorption.
Sonexos plans to use the new capital to advance its technology from engineered prototypes to industrial products. The funding will support customer integration programmes, reliability testing, product qualification and regulatory compliance.
The investment will also finance the expansion of its engineering and applications teams in Switzerland and internationally, alongside broader intellectual property protection.
Sonexos is conducting paid prototype integration programmes with appliance and HVAC manufacturers. According to the company, its most advanced programmes are targeting series production in early 2028, subject to product integration and qualification requirements.
The company is also developing applications for data centre cooling systems. In July 2026, Sonexos announced a collaboration with Italian technology company SIT to integrate its noise control technology with fan platforms used in data centres, energy storage and industrial cooling.
