ETRI surpasses the limitations of robotic hands with omnidirectional tactile sensors

ETRI researchers have successfully developed a robotic finger capable of precisely detecting omnidirectional pressure. The development of intelligent robotic hand technology, which can adjust its grip strength according to the stiffness of objects, is expected to bring about innovation in ultra-precise object recognition.

The Electronics and Telecommunications Research Institute (ETRI) announced the development of a new tactile sensor technology that can very precisely detect pressure regardless of the direction applied. The commercialization timeline is anticipated for the latter half of this year, following technology transfer.

ETRI has entered into a mutual cooperation agreement with Wonik Robotics¹⁾ and jointly exhibited related achievements at the 『Smart Factory & Automotive Industry Exhibition (SFAW 2024²⁾)』 held at COEX in Seoul for three days starting from the 27th of last month.
^{1) The company that developed the ‘Allegro Hand,’ a robotic hand product, is the global market leader in robotic hands, supplying to Big Tech companies such as Meta Platforms, Google, Nvidia, Microsoft, and Boston Dynamics.
2) SFAW (Smart Factory + Automation World) is the leading international exhibition in Asia for the smart factory and automation industry sector.}

The tactile sensor technology introduced by ETRI features a robotic finger with stiffness (modulus³⁾) and shape similar to that of a human finger. It is capable of flexibly handling everything from hard objects to deformable soft objects.
^{3) Stiffness is one of the characteristics that indicate the hardness or softness of a material, represented numerically and commonly referred to as the modulus of elasticity or elastic modulus.}

The research team has explained that this technology overcomes the technical limitations of pressure sensors applied to existing 3D-shaped robotic fingers, which previously showed distorted signals depending on the direction in which the object was grasped. It is also highly rated for its performance and reliability, marking a new era in the intelligence of robotic hand technology.

The core of this technology lies in its ability to precisely detect pressure from various directions even in a three-dimensional finger form, while simultaneously providing the flexibility to handle objects as naturally as a human hand.

The research team explained that this robotic finger technology has been advanced by integrating omnidirectional pressure sensing with flexible air chamber tactile sensor technology, high-resolution signal processing circuit technology, and intelligent algorithm technology capable of real-time determination of an object’s stiffness.

With the development of this robot finger equipped with an omnidirectional tactile sensor, the researchers anticipate that robots will be able to perform more complex and delicate tasks in various fields, including manufacturing and service sectors.

ETRI expects that, through tactile sensor technology, robots will be able to manipulate a wide range of objects more precisely and significantly improve interaction with humans.

The researchers have enhanced the sensor’s precision in pressure detection by developing a robotic finger that changes LED colors according to pressure changes, providing intuitive feedback to users. By integrating vibration detection and wireless communication capabilities, communication between robots and humans has been further strengthened.

Moreover, the sensor developed by the research team is not directly exposed to the area where pressure is applied, allowing for stable operation over long periods even with continuous contact, similar to a robot hand. This improves the scalability of applications for robotic hands. Traditional tactile sensors, which have sensors directly placed in the area where pressure is applied, tended to have a higher probability of malfunction.

Kim Hye-jin, a principal researcher at ETRI’s Intelligent Components and Sensors Research Section, stated, “This sensor technology advances the interaction between robots and humans by a significant step and lays the groundwork for robots to be more deeply integrated into our society and industries.”

In the future, the research team plans to develop not just a single joint of a finger but an entire robotic hand that has a tactile sense similar to that of a human. Additionally, they aim to extend their development to a super-sensory hand that surpasses human sensory capabilities, including not only pressure but also temperature, humidity, light, and ultrasound.

Through their collaboration with Wonik Robotics, they have developed a robotic hand capable of recognizing objects through tactile sensors and flexibly controlling force. This research achievement is regarded as an innovative technology that significantly advances the tactile capabilities of robots. The research team plans to continue various studies to enable robots to handle objects and perceive the world as human hands do through sensors.

Last year, the researchers developed an intelligent robot gripper technology capable of determining the size and freshness of tomatoes by touch, successfully distinguishing between 11 types of tomatoes with 98.7% accuracy based on tactile information.

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This research was conducted as part of the “Development of a Flexible Tension Hybrid Sensor Platform Technology for Freeform High-density Integrated Sensors,” supported by the Ministry of Trade, Industry and Energy, and the Korea Evaluation Institute of Industrial Technology (KEIT).

About Electronics and Telecommunications Research Institute (ETRI)

ETRI is a non-profit government-funded research institute. Since its foundation in 1976, ETRI, a global ICT research institute, has been making its immense effort to provide Korea a remarkable growth in the field of ICT industry. ETRI delivers Korea as one of the top ICT nations in the World, by unceasingly developing world’s first and best technologies