Related Experiment Video
Updated: Feb 12, 2026
08:20
In Situ Soil Moisture Sensors in Undisturbed Soils
Published on: November 18, 2022
7.5K
Miniaturized flexible skin moisture sensor with optimized coil for enhanced wireless power efficiency
Jeonghyun Kim1, Seongu Kim1, Changyu Yeo2
1Department of Electronic Convergence Engineering, Kwangwoon University, Seoul, 01897, South Korea.
Scientific Reports
|February 10, 2026
Summary
Optimizing miniature antenna coils is key for reliable, battery-free wearable sensors. This study presents a design for a skin hydration sensor that maintains performance despite bending, ensuring stable power and data communication.
Area of Science:
- Wearable technology
- Biomedical engineering
- Wireless communication
Background:
- Efficient wireless power transfer is crucial for battery-free wearable sensors.
- Antenna coil performance significantly impacts Near Field Communication (NFC) sensor efficiency and data reliability.
- Miniaturization of sensors often compromises coil performance and communication sensitivity.
Purpose of the Study:
- To optimize the design of a miniature antenna coil for a wearable skin hydration sensor.
- To ensure stable resonant frequency, power reception, and data communication under mechanical deformation.
- To develop a compact, durable, battery-free sensor platform for real-time monitoring.
Main Methods:
- Coil design and optimization for miniature wearable sensors.
- Experimental validation of antenna coil performance under bending conditions.
- Integration of the optimized coil into a battery-free skin hydration sensor platform.
- Environmental testing and polydimethylsiloxane (PDMS) encapsulation for durability.
Main Results:
- An optimized miniature antenna coil design was achieved for wearable sensors.
- Stable resonant frequency, power reception, and data communication were maintained even with mechanical deformation.
- A compact, battery-free sensor platform for real-time skin hydration monitoring was successfully developed.
- The sensor platform demonstrated mechanical durability and long-term stability through rigorous testing.
Conclusions:
- Coil optimization is critical for next-generation wearable healthcare devices.
- The developed sensor platform enables reliable, real-time skin hydration monitoring.
- The study provides a foundational design framework for miniature sensor systems.
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