“Hey, Siri, how’s the weather today?” Voice recognition technology is increasingly prevalent in our daily lives, ranging from asking trivial questions, playing music, sending text messages to controlling GPS navigation systems. It is a convenient technology with wide applications. However, to make the most of its intended functions, one must stand close to the device and articulate carefully. What if the skin on our body could recognize sounds without any equipment?
Professor Kilwon Cho and Dr. Seong Lee from the Department of Chemical Engineering, together with Professor Wonkyu Moon and Dr. Junsu Kim from the Department of Mechanical Engineering at Postech, have developed a microphone that detects sound by applying polymeric materials to microelectro-mechanical systems. Is. MEMS)
The newly developed microphone exhibits a wider hearing area than human ears, while it is surprisingly small and thin in size that can be easily attached to the skin. This academic achievement was recently presented as the Inside Back Cover Paper advanced MaterialsAn international magazine on content.
Traditional MEMS-based microphones, used in cellular phones, Bluetooth devices, and others, have thin, small and sophisticated diaphragm structures. However, being made of hard and brittle silicone, the diaphragm or microphone is difficult to bend at will and interferes with the device’s voice recognition capability.
The research team overcame this limitation by creating a MEMS-based microphone structure using a polymer material more flexible than silicon and that can be designed into any shape. The size of the device is a quarter that of a nail and its thickness is only a few hundred micrometers (μm, 1μm = one million metres). Microphones can be applied to large surface areas of the body or even to the finger as if it were real human skin.
According to the study, the hearing sensitivity of microphones is higher than that of human ears, while recognizing the surrounding sounds and the user’s voice without distortion. In addition, it can detect both loud sounds higher than 85 decibels, a threshold that causes hearing damage, and low-frequency sounds that humans cannot hear.
Voice detection quality is on par with a cellular phone or studio microphone. When the acoustic sensor on the skin was connected to a commercial voice assistant program (Google Assistant), the user could easily search, translate and control the devices.
The new acoustic sensor has potential applications in wearable voice recognition devices for the Internet of Things (IoT) and human-machine interfaces. The research team plans to build the auditory electronic skin by integrating it with skin-attached pressure and temperature sensors, flexible displays, and more.
This study was supported by the National Research Foundation of Korea and the Korea Evaluation Institute of Industrial Technology (KEIT).
material provided by Pohang University of Science and Technology (POSTECH), Note: Content can be edited for style and length.