E-Nose for Odor Detection of Humanoid Robots Based on Micro Opto-Mechatronics Sensors

The olfactory ability of humanoid robots makes them more human, it gives them one of the five main senses. A scalable sensor prototype based on an optical phenomenon known as whispering gallery modes (WGMs) in polymeric resonators was designed for odorant detection. The olfactory sensor will act as an electronic nose (E-Nose) for the humanoid robots. The polydimethylsiloxane (PDMS) is the main material for the proposed sensor; once the odorant starts to propagates inside this polymeric material it will leads to a change in the sensors morphology then the detection for the odor will be captured based on the corresponding shift on the transmission spectrum for the wavelengths of the WGM. To increase the reliability and lifetime of the sensor, the polymeric cavity was created and sealed from the environment with a permeable PDMS membrane which only allows odor to reach the polymeric resonator. A study was conducted using PDMS membranes of different thicknesses to verify and study the sensor sensitivity. Also, a tracking algorithm based on signal cross-correlation was used for accurate WGM wavelength shift quantification which can also be programmed on a real-time platform for portability. This allows for easy utilization of the WGM as an olfactory prosthetic.