An Electromechanical System Based on Carbon Nanotube Sensors to Detect Apnea

A sensitive breath sensor for real-time detection of apnea is important in medical care. We aim to construct a flexible platform with integration of carbon nanotubes (CNTs) and related electromechanical system for the respiratory care. Through acid-treated process, multiwalled carbon nanotubes (MWCNTs) are immobilized on the heated silicon wafer. Chromium and gold are then implemented on the MWCNT film to develop micro interdigitated electrodes as a base of the sensor. The mini-sensor is mounted in a connecting tube and equipped to a programmed microchip processor to become a warning detector for apnea, namely less than six breaths per minute. Volunteers are enrolled for testing the effectiveness of this novel electromechanical device. In this paper, there are five volunteers, three males and two females, enrolled in this experiment. The sensor under an open system is reactive to exhaled flow but less responsive to inhaled flow or ambient noises. Responses of the MWCNT sensor to exhaled breaths showed unique performance parameters, strength, frequency, flow rate, and components. With variable simulated tests, the results showed that this MWCNT-based system could accurately evoke warning signals (100% of sensitivity rate), indicating its effectiveness and usefulness for detection of apnea. Current results prove that a CNT-based sensor by integrated techniques could effectively detect apnea under an open system. This mini-sensor along with the whole flexible system may be modified with variable extended designs suitable for the respiratory care in the future.