A smart sniffing shoes based on embroidered sensor array

A prototype of smart sniffing shoes with wireless data communication has been developed as a wearable medical instrument. This intelligent system can be divided into two major parts: (i) chemical gas sensor array installed inside the shoes for foot health monitoring and (ii) wireless data communication using ZigBee technology. The gas sensors for odor sensing were created by embroidering the sensing materials onto a fabric substrate then installed inside the tongue of shoes. Moreover, it was designed as a removable system, convenient for maintenance and cleansing. The embroidered sensor array has been tested with various single chemical components of volatile organic compounds (VOCs) with low concentration in a static system. It was found that these sensors could provide a good sensitivity and fast recovery even operated at the room temperature. For preliminary testing on an actual application, this wearable e-nose system was applied to monitor the foot odors, of which results have demonstrated that this system could distinguish foot odors in each duration time. Principal component analysis (PCA) was used to confirm the classification of individual foot health.