SensiBel, an Oslo, Norway-based microphone technology company, closed a €15 million (~$15.8 million) funding round to ramp up production of its optical MEMS microphone technology. TRUMPF Venture GmbH led the funding round, which sensiBel said will additionally support development and research activities. MEMS microphones will be sensiBel’s first type of products, and they will use the company’s patented complete optical MEMS readout technology. The sensiBel microphones are only a few millimeters in size, making them just as compact as other MEMS-based solutions on the market. MEMS microphones are found in consumer electronics, medical devices, and applications in the automotive industry. They function by means of a membrane that is set in motion by sound waves. In the case of a conventional, capacitive MEMS microphone, this movement of the membrane is measured on the basis of changes to an electrical field between the movable membrane and a rigid backplate. By contrast, the optical system in the sensiBel microphone uses lightwaves to measure this movement. Light is projected onto the membrane, via a diffraction grating, by means of a VCSEL. This light is reflected and then captured and analyzed by photodiodes. SensiBel has developed an optical MEMS microphone that is only a few millimeters in size. The company has received €15 million from investors including TRUMPF. Courtesy of sensiBel via TRUMPF. Unlike the conventional method, this optical technology enables the measurement of very small movements of the membrane and therefore very low levels of noise. TRUMPF, in announcing its investment, said experts forecast a market volume for MEMS microphones of 8 billion units in 2022. “TRUMPF Venture is investing in sensiBel and will also provide strong support in the area of photonics,” said Dieter Kraft, managing director of TRUMPF Venture GmbH. “The optical MEMS microphone developed by sensiBel marks a real breakthrough capable of delivering studio-quality sound recordings. This technology enables speech recognition over greater distances and also in loud environments.” The investment round led by TRUMPF Venture involved the fund of the European Innovation Council and other venture capital investors from Norway. SensiBel’s optical MEMS technology can additionally be used in other MEMS products, such as accelerometers. The company has about 20 employees.