In recent years, there has been a rapid increase in the demand for stretchable strain sensors used for detecting human motion. These sensors have a wide range of applications, from wearable technology to healthcare monitoring devices. In response to this growing demand, our latest research introduces high-performance strain sensors constructed from a hybrid material of silver (Ag) flakes and Ag nanocrystals (NCs) embedded in a polydimethylsiloxane (PDMS) elastomer. This innovative combination results in sensors that are both highly sensitive and durable.
Enhanced Electrical Conductivity and Sensitivity
The addition of Ag nanocrystals into the Ag flake network significantly enhances the electrical conductivity and sensitivity of the strain sensors. This hybrid material effectively combines the properties of both components to achieve superior performance. The Ag flakes provide a conductive network, while the Ag NCs improve the overall conductivity and response to strain.
Efficient Sintering with Intense Pulsed Light
A key feature of our method is the use of intense pulsed light (IPL) irradiation to induce localized heating of the Ag flakes and NCs. This process achieves efficient sintering of the Ag nanocrystals within seconds, without causing any damage to the PDMS matrix. The IPL technique not only enhances the sensor’s sensitivity but also ensures that the PDMS elastomer retains its mechanical properties.
High Stretchability and Mechanical Stability
Our strain sensors are designed to be highly stretchable, with a maximum strain of 80%. They also exhibit a high gauge factor of 7.1, indicating their sensitivity to strain. Moreover, these sensors maintain their performance over 10,000 stretching cycles under 50% strain, demonstrating exceptional mechanical stability and durability.
Practical Applications
To showcase the practical applications of our high-performance strain sensors, we have fabricated a smart glove and a sports band. The smart glove is capable of detecting finger motions, making it useful for gesture recognition and virtual reality applications. The sports band can measure the applied arm strength, which is valuable for fitness tracking and rehabilitation purposes. These demonstrations highlight the potential of our sensors in various real-world scenarios.
Conclusion
Our study provides an effective method for fabricating elastomer-based high-performance stretchable electronics. By incorporating Ag nanocrystals into an Ag flake network and using IPL irradiation for sintering, we have developed sensors that are highly sensitive, stretchable, and mechanically stable. This advancement opens new possibilities for wearable technology and other applications requiring reliable strain detection. / Journal cover design by Scapiens
