The development of increasingly advanced sensors is driving progress in fields such as robotics, security systems, virtual reality (VR), and high-tech prosthetics. Among these, multimodal tactile sensors—which detect various types of touch-related data like pressure, texture, and material composition—stand out for their potential to replicate the human sense of touch.
Despite significant advances in tactile sensor technology, two major challenges persist: detecting both the direction and magnitude of applied forces, and accurately identifying the materials that objects or surfaces are made from. Many existing sensors struggle to overcome these limitations.
Addressing this gap, a team of researchers from the Chinese Academy of Sciences has developed a new multimodal tactile sensor inspired by the human fingertip. Detailed in a recent paper published in Advanced Materials, the novel sensor not only determines the direction of forces applied to it, but also distinguishes between 12 commonly encountered materials with high precision.
“Multimodal tactile perception is crucial for advancing human–computer interaction, but real-time multidimensional force detection and material identification remain challenging,” write Chengcheng Han, Zhi Cao, and their colleagues.
Their innovative solution is a finger-shaped tactile sensor (FTS) based on the triboelectric effect, which generates electric signals in response to contact and motion. The sensor mimics the anatomical structure of a fingertip and is built with two main components:
- An outer layer, designed for material identification, embeds three different materials into the surface of a silicone shell to form single-electrode sensors.
- An inner structure handles force sensing, featuring a conductive silver paste shielding layer, four silicone microneedle arrays, a silicone bump, and five silver electrodes fixed to a polylactic acid skeleton. These components are linked via interlocking structures that enable localized contact and separation, allowing the system to detect the direction of force via signal changes from the electrodes.
The team tested the FTS through simulations and real-world experiments, including integrating the sensor with a robotic hand. Using data analysis tools like LabVIEW and Jupyter, the robotic system achieved an impressive 98.33% material recognition accuracy. The sensor also effectively detected different force directions and magnitudes in real-time.
“Integrated into a robotic hand, the FTS enables real-time material identification and force detection in an intelligent sorting environment,” the researchers note. “This research holds great potential for applications in tactile perception for intelligent robotics.”
The promising results suggest the FTS could significantly improve the tactile abilities of humanoid robots, smart prosthetics, and other interactive technologies. Future enhancements may allow the sensor to recognize even more materials and capture a broader range of tactile information, paving the way for machines with a more human-like sense of touch.
By Impact Lab
