Battery-less NFC Sensors for the Internet of Things

3Case Study 2: Smart Diaper

3.1. Motivation

The main objective of this chapter is to present the application of NFC in diapers. To this end, we propose a smart diaper based on a wet detector, which is integrated in a battery-less NFC tag to be read from a smartphone.

Diapers are used to absorb moisture not only in babies but also in people like the elderly who have difficulty controlling their bladders or bowel movements or who are unable to get to a toilet quickly, such as bedridden people and those in a wheelchair. Since average life expectancy is increasing, the elderly population has grown, and the number of people who require extra care is increasing (WHO 1998; Wai et al. 2012). Sometimes, it is difficult to check the state of the diaper in babies and the elderly without removing their clothes. Nurses and other caregivers spend a lot of time performing this task. Therefore, optimizing this process can help reduce the cost of health services. Diapers must be changed to prevent skin rash caused by the skin being exposed for a long time to wetness and the high pH levels of urine and feces (Berg et al. 1994). It is therefore important to reduce the time that the moisture is in contact with the skin by regularly replacing the diaper (Adam 2008). Skin rash is often avoided by adding absorbent gels, but these can cause side effects such as irritation and allergies. Consequently, the use of smart diapers or normal diapers that include reusable tags may be of interest, and this ...