Samsung Electronics’ Research in Collaboration with Ajou University Demonstrates the Next-Generation Multifunctional Artificial Muscle Actuator
Samsung Electronics today announced that Dr. Bongsu Shin (co-first author) of Samsung Research1 published an article titled “Actuation of compact wearable augmented reality devices by a multifunctional artificial muscle” in the world renowned journal ‘Nature Communications.’
This project was carried out in partnership with the Mechanical Engineering team of the University of Ajou, led by Professor Je-Sung Koh (corresponding author) based in Korea. The joint research team has developed an artificial muscle actuator that can be applied to augmented reality (AR) glasses and adapt naturally to haptic gloves.
With the growing popularity of the metaverse, actuator and sensor technologies are rapidly evolving to create an even more immersive experience in virtual worlds. Actuators and sensors embedded in portable devices must be compact and lightweight because the devices are carried by users and often require mobility. The conventional actuator had some limitations in realizing more advanced functionality, as a thin form factor and high power density would be difficult to achieve for conventional types.
The research team proposes an artificial muscle actuator that solves practical engineering challenges, which are limited to conventional types such as electromagnetic actuators. An artificial muscle actuator can function as a small-scale, high-power actuation system with sensing capability to develop wearable devices such as multifocal AR glasses and naturally fitting haptic gloves. The research team designed a lightweight and powerful shape-memory alloy (SMA) muscle actuator, called the Conformal Amplified SMA Actuator (CASA). The newly developed version is lightweight (0.22g) but strong enough to lift a weight 800 times heavier than itself.
“This new actuator we are offering is lightweight, compact yet powerful in terms of strength to weight ratio. It is significant that the new actuator has overcome the limitations of conventional actuators, while bringing the potential of its broad applications ranging from robotics to wearable devices,” said Dr. Bongsu Shin of Samsung Research. “We anticipate that the result of our latest research will be the core hardware technology for a more immersive and interactive experience for the next generation.”
The team also demonstrated how the actuator enables image depth control. Binary depth switching is adopted to reduce vergence accommodation conflict (VAC), which may cause eyestrain for some AR glasses users, by directly adjusting the distance between the display and the optical system of the prototype of AR glasses depending on the focus distance of the object. to project.
Additionally, non-vibrating mechanotactile outputs are important for generating natural and expressive tactile sensations on the skin through haptic devices. To convey the sensation of large skin deformation, haptic devices require actuators with a high force-to-weight ratio and large displacement. Combining multiple actuators within the limited area of the haptic device prototype also enables more expressive tactile experiences.
CASA triggers an action on an object with pressure and measures pressure without a sensor using a feature of artificial muscle whose electrical resistance varies in response to external pressure. The CASA-equipped haptic glove prototype is so thin and pressure sensitive that it has the potential to be applied to telehaptics which recognizes expressions made by the tactile writing system and converts them into electrical signals.
1 Samsung Research, acting as Samsung Electronics’ advanced R&D center, leads the development of future technologies for the company’s Device eXperience (DX) division.