Soft Wireless Passive Chipless Sensors for Biological Applications: A Review

Area of Science:

• Biomedical Engineering
• Sensor Technology
• Wireless Communication

Background:

• Soft wireless passive sensors are advantageous for biological and engineering applications due to their lack of external power requirements and capability for remote data transmission.
• These sensors acquire external information through electromagnetic induction using external coils.

Purpose of the Study:

• To review the biological applications of soft wireless passive chipless sensors.
• To classify wireless passive sensors and explain their core functionalities.
• To provide an overview of the main advancements in this field.

Main Methods:

• Classification of soft wireless sensors into three main types: LC-resonant, radio frequency (RF), and surface acoustic wave (SAW) sensors.
• Explanation of the working principles, equivalent circuits, and biological applications for each sensor type.
• Discussion of the underlying physics, including electromagnetic induction and piezoelectric principles.

Main Results:

• LC-resonant sensors measure physical quantities by correlating frequency resonance with the monitored object.
• RF sensors utilize electromagnetic fields for wireless measurement and data exchange of physical parameters.
• SAW sensors employ piezoelectric substrates and guided waves for physical parameter monitoring.

Conclusions:

• Soft wireless passive sensors are designed for unobtrusive biological health monitoring.
• They eliminate the need for external power supplies and wired communication, enhancing user convenience.
• These sensors represent a significant advancement in remote and non-invasive health diagnostics.