# A Survey of NFC Sensors Based on Energy Harvesting for IoT Applications
## 3 NFC Sensors
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Reference** & **Application** & **IC** & **Passive** & **Comments** \\ \hline
[29] & Cold-chain temperature & \
\begin{tabular}{c} NFC-WISP \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} Optional E-ink display \\ Discrete rectifier \\ \end{tabular} \\ \hline
[55] & Temperature &
\begin{tabular}{c} NFC-WISP \\ (ISO14443) \\ \end{tabular} & N & Measurement of newborn temperature in an incubator \\ \hline
[56] & Cold-chain temperature &
\begin{tabular}{c} MLX30129 \\ (ISO15693) \\ \end{tabular} & Y & Critical temperature indicator based on melting point \\ \hline
[60] & \begin{tabular}{c} Biopatch \\ body temperature \\ \end{tabular} & \
\begin{tabular}{c} RF430 FRL152H \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} Can be used as data logger if the battery is used \\ Temperature measurement using thermistors \\ \end{tabular} \\ \hline
[61] & \begin{tabular}{c} Tattoo \\ body temperature and light \\ \end{tabular} & \
\begin{tabular}{c} RF430 FRL152H \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} Low-cost lattoo-like stretchable \\ \end{tabular} \\ \hline
[62] & \begin{tabular}{c} Sweat, NaCl concentration \\ \end{tabular} & \
\begin{tabular}{c} MLX90129 \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} Measures the potential between two electrodes for NaCl \\ concentration in the sweat \\ \end{tabular} \\ \hline
[63] & \begin{tabular}{c} Biopatch \\ pH \\ \end{tabular} & \
\begin{tabular}{c} SL13 \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} Microfluidic electrodes \\ \end{tabular} \\ \hline
[64] & \begin{tabular}{c} PH \\ \end{tabular} & \
\begin{tabular}{c} SL4310 \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} ASIC with a \(3\times 3\) array of ISFET \\ \end{tabular} \\ \hline
[65] & ECG & \
\begin{tabular}{c} Custom ASIC \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} Powered from energy-harvesting TEG \\ and supercapacitor. \\ \end{tabular} \\ \hline
[66] & Implantable glucose monitor & \
\begin{tabular}{c} Custom ASIC \\ (ISO14443) \\ \end{tabular} & N &
\begin{tabular}{c} Glucose concentration is encoded in the \\ modulating frequency \\ Semi-passive \\ \end{tabular} \\ \hline
[67] & Glucose monitor & \
\begin{tabular}{c} Custom ASIC \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} micro-fluorimeter. \\ \end{tabular} \\ \hline
[68] & \begin{tabular}{c} Status food monitoring \\ Multigas sensor \\ \end{tabular} & \
\begin{tabular}{c} SL13 \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} PIC16 LF1703 microcontroller, \\ Color detector S11059-02 DT \\ \end{tabular} \\ \hline
[69] & Gas sensor & \
\begin{tabular}{c} Modified inlay \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} Functionalized SWCNTs \\ On/off detection based on a change in the \\ resonance frequency \\ \end{tabular} \\ \hline
[70] & Tire pressure & \
\begin{tabular}{c} Custom ASIC \\ (ISO14443) \\ \end{tabular} & Y &
\begin{tabular}{c} MEMS capacitive sensor \\ \end{tabular} \\ \hline
[71] & \begin{tabular}{c} Temperature, humidity, \\ soil moisture \\ \end{tabular} & \
\begin{tabular}{c} M24 LR04E-R \\ (ISO15693) \\ \end{tabular} & Y &
\begin{tabular}{c} Atinity85 microcontroller \\ LM75A temperature sensor \\ HIH-5030 humidity sensor \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of NFC-based sensors in the literature. Y—yes; N—no; ASIC—application-specific integrated circuit; ISFET—ion-sensitive field-effect transistor; ECG—electrocardiogram; TEG—thermoelectric generator; SWCNT—single-walled carbon nanotube; MEMS—microelectromechanical system. A biopatch for continuously monitoring hydration was reported in Reference [62]. The sensor, which measures the concentration of NaCl in sweat, was based on Melexis MLX90129, which is used for the potentiometric sensing of electrolytes in sweat, reading surface temperature, and sensing the potential difference between two electrodes. The flexible printed circuit board (PCB) was built from Dupont Pyralux.