Summary:
Researchers in the Department of Electrical and Computer Engineering at UCLA have developed a non-contact force sensor that relies on laser speckle imaging to precisely sense changing forces on the surface of a variety of materials.
Background:
Force sensing capabilities enable the ubiquity of a wide range of modern technologies, from touch screen in consumer electronics and autonomous vehicles to robotics feedback systems. Useful information can be obtained from such forces, such as the weight of an object or a user’s intent, which can serve as new channels of information for intelligent interaction systems. Demand for smart force sensors is rapidly growing, particularly with the advent of the Internet of Things (IoT). Conventional force sensors rely on contact sensors made of pressure-sensitive materials such as piezo films and discs or force-sensitive resistors. These contact-based sensors either require wiring, which offers little flexibility in its application, or operate on battery-powered, wirelessly-enabled systems which are costly to scale up. Additionally, contact-based sensors are sensitive when exposed to natural elements (e.g., moisture, rain), making repairs and replacement costly. These drawbacks further limit their potential applications for low-cost and passive objects such as 3D prints and room utilities. Additionally, contact-based sensors, on many occasions, might not be preferable to on-body interactions. There is an unmet need to produce a low-cost and robust non-contact force sensor that can be used in many environments for a wide array of applications.
Innovation:
Professor Zhang and his research group have developed a non-contact force sensor bundle and processing algorithms to detect and quantify applied forces with high precision and accuracy. This invention, titled ForceSight enables ubiquitous fine-grain touch experience, a key interaction in everyday environments. The sensing capabilities of the minute surface deformations without users’ exaggerated motions are realized by utilizing laser speckle imaging technologies. The principal phenomenon that this innovation relies on the discovery that surfaces of materials deform in the presence of force. These minute deformations can be quantified using an algorithm developed by Professor Zhang. The force sensor can be implemented on different everyday surfaces (wood, plastic, and metal) and exhibits high accuracy amongst these materials, and is robust to various sensing distances and calibration methods. This technology has been demonstrated in many real-world applications, including force-based material identification, touch screen sensing, and implementation as a force-sensor into 3D-printed materials. Implementation costs are negligible, as the entire sensor bundle costs less than $10 to manufacture. This novel force sensing tool has a simple setup with precise and accurate performance, and it can readily fulfill the growing market needs for non-contact based smart force sensing technologies.
Demonstration Video: ForceSight: Non-Contact Force Sensing with Laser Speckle Imaging
Potential Applications:
• Electronic touch screen sensors
• Robotic sensors
• Automobile sensors
• 3D printing interactivity
• Material identification/material-aware cutting
• Internet of Things (IoT)
Advantages:
• Non-contact-based technology
• Fine-grain touch sensing ability (sub-centimeter)
• Simple design and flexible deployment
• Easily transferable to different materials/surfaces with accurate performance
• Cost-effective
• Robust to errors
Development to Date:
First description of complete invention completed April 2022.
Reference:
UCLA Case No. 2022-284
Lead Inventor:
Prof. Yang Zhang