Pressure sensors with wireless operation

Application

• Wearable electronic devices
• Electronic Skin for Robots
• Biomedical

Development Status

• Pressure sensor prototype demonstrator and results
• Undergoing further development for a range of sensing uses

IP Status

• PCT application filed

Commercial Offering

• Licensing and/or collaborative research

Opportunity

The current market of pressure sensors in wearable applications that are commonly used to monitor sports and medical garments is limited in terms of their performance characteristics. In most cases, there are issues with the sensors’ reliability and reusability; devices are impractical to use owing to their size and bulky wiring restrictions, and they are frequently not capable of delivering reliable measurements over wide pressure ranges.

Our innovation goes beyond the conventional approach and offers a low-cost alternative with reduced fabrication complexity, combined with improved sensitivity to low pressures, wireless operation, and improved sensor flexibility. This approach will have a substantial impact in applications related to compression garments for medical treatment, or for improved performance in sports. It also has wider applications in pressure-sensing, including electronic skin for robotics.

Technology Overview

The novel pressure sensor developed by the School of Engineering at the University of Edinburgh and Heriot-Watt University is based on a flexible inductor-capacitor (LC) circuit that is designed to resonate at a specific frequency.

The sensor is passive, requiring no power supply. Its resonant frequency shifts upon changes in applied pressure, and is detected wirelessly via an external antenna and portable reader system.

The operational resonant frequency and the range of sensitivity can both be independently modified through simple design of the micropatterned electrodes and internal sensor microstructure. The LC pressure sensor is manufactured using a unique and scalable microfabrication process, which yields flexible devices capable of withstanding extreme deformations such as bending and folding.

Devices are manufactured using bottom-up processing from a single silicon (Si) carrier wafer, allowing concurrent development of multiple batches with a high degree of translational and angular alignment, and are later peeled from the carrier wafer to yield ultrathin, highly flexible and conformable devices.

Their fabrication involves standard semiconductor processing steps, including surface (plasma) treatments, material deposition, photolithography and etching. This patent-pending approach enables high device flexibility, manufacturing precision, uniformity, and mass wafer treatment for large-scale manufacturing.

Benefits

• LC wireless operation technology – no battery supply requirements
• Readily integratable with existing technologies
• Stability to iterative compressive deformation, delamination, severe bending (≤1mm radius) and 1800 folding of the pressure sensors
• Ultra-thin sensors (< 100 µm), and highly flexible and conformable
• Biocompatible materials, for biomedical and other wearable applications
• Scalable manufacturing process, therefore, cost-effective

Publication

International patent application: WO2021171037A1

This technology was developed between the University of Edinburgh and Heriot-Watt University.

Please note: the header image is purely illustrative. Only use images with permission.

Quote: TEC1104167