3D Micro Strain Gauges: Researchers from Peking University have made significant strides in the development of flexible, modular tactile sensors that adhere to the skin, capable of detecting biomechanical signals from various body parts. Their findings were published in Science Advances, showcasing sensors that enable high-density pressure mapping, wireless monitoring of biomechanical signals, and independent measurement of temperature, normal force, and shear force.
Han Mengdi, the study’s corresponding author, explained that the sensors utilize 3D micro strain gauges to expand the capabilities of tactile sensors and electronic skins. By converting traditional planar strain gauges into 3D structures, which are compatible with lithographic processes, the researchers have increased the spatial density of tactile sensing, allowing for more complex sensing modalities.
The 3D micro strain gauges use thin film stress and demonstrate excellent consistency and stability. Their manufacturing process is fully compatible with microfabrication techniques and integrates smoothly with microelectronics, ensuring scalability and efficiency in production.
Ph.D. student Chen Xu, a co-first author of the study, highlighted that the performance of these sensors can be easily customized. By modifying the shape of the 3D microstructures, adjusting the thickness of the thin films, and fine-tuning the encapsulating polymer, the team can tailor the sensors to specific applications.
Each sensor includes four 3D micro strain gauges arranged orthogonally, enabling precise measurement of normal and shear forces. These gauges, along with a temperature sensing module, allow for accurate detection of external forces’ magnitude and direction. Additionally, an anti-crosstalk circuit was designed to map spatiotemporal forces at the skin interface, ensuring clear signal readings.
This new technology holds promise across multiple fields, including robotics, biomedicine, and consumer electronics. The 3D micro strain gauges’ compatibility with both microelectronics and macroelectronics makes them a key development in improving the functionality of flexible tactile sensors and electronic skins. The researchers see vast potential for this technology in advancing sensing solutions across industries.
More information: Chen Xu et al, Three-dimensional micro strain gauges as flexible, modular tactile sensors for versatile integration with micro- and macroelectronics, Science Advances (2024). DOI: 10.1126/sciadv.adp6094
Journal information: Science Advances
