A research team from the National University of Singapore (NUS), led by Assistant Professor Chen Po-Yen, has taken the first step towards improving the safety and precision of industrial robotic arms by developing a new range of nanomaterial strain sensors that are 10 times more sensitive when measuring minute movements, compared to existing technology.
Fabricated using flexible, stretchable, and electrically conductive nanomaterials called MXenes, these novel strain sensors developed by the NUS team are ultra-thin, battery-free and can transmit data wirelessly. With these desirable properties, the novel strain sensors can potentially be used for a wide range of applications.
NUS researchers have developed wireless, ultra-thin and battery-free strain sensors that are 10 times more sensitive than conventional technologies. These light-weight strain sensors can be incorporated into rehabilitation gloves to improve their sensitivity and performance.
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Assistant Professor Chen, who is from the NUS Department of Chemical and Biomolecular Engineering, explained, "Performance of conventional strain sensors has always been limited by the nature of sensing materials used, and users have limited options of customising the sensors for specific applications. In this work, we have developed a facile strategy to control the surface textures of MXenes, and this enabled us to control the sensing performance of strain sensors for various soft exoskeletons. The sensor design principles developed in this work will significantly enhance the performance of electronic skins and soft robots."
These strain sensors developed by NUS researchers can be coated on a robotic arm like an electronic skin to measure subtle movements as they are stretched. When placed along the joints of robotic arms, these strain sensors allow the system to understand precisely how much the robotic arms are moving and their current position relative to the resting state. Current off-the-shelf strain sensors do not have the required accuracy and sensitivity to carry out this function.
Conventional automated robotic arms used in precision manufacturing require external cameras aimed at them from different angles to help track their positioning and movement. The ultra-sensitive strain sensors developed by the NUS team will help improve the overall safety of robotic arms by providing automated feedback on precise movements with an error margin below one degree and remove the need for external cameras as they can track positioning and movement without any visual input.
The technological breakthrough is the development of a production process that allows NUS researchers to create highly customisable ultra-sensitive sensors over a wide working window with high signal-to-noise ratios.
This production process allows the team to customise their sensors to any working window between 0 to 900 per cent, while maintaining high sensitivity and signal-to-noise ratio. Standard sensors can typically achieve a range of up to 100 per cent. By combining multiple sensors with different working windows, NUS researchers can create a single ultra-sensitive sensor that would otherwise be impossible to achieve.
"These advanced flexible sensors give our soft wearable robots an important capability in sensing patient's motor performance, particularly in terms of their range of motion. This will ultimately enable the soft robot to better understand the patient's ability and provide the necessary assistance to their hand movements," said Associate Professor Raye Yeow, who heads a soft robotics lab in NUS Department of Biomedical Engineering and leads the Soft and Hybrid Robotics programme under the National Robotics R&D Programme Office.
The team is also looking to improve the sensor's capabilities and work with the Singapore General Hospital to explore the application in soft exoskeleton robots for rehabilitation and in surgical robots for transoral robotic surgery.
MEDICA.com; Source: National University of Singapore