Samsung Electronics Research in Collaboration with Ajou University Demonstrates Next-Generation Multifunctional Artificial Muscle Actuator
Samsung Electronics today announced that Dr. Bongsu Shin (co-first author) at Samsung Research1 published an article titled “Actuation of compact portable augmented reality devices by means of multifunctional artificial muscles” in the world-renowned magazine ‘Nature Communications’.
This project was carried out in association with the mechanical engineering team at Ajou University, led by Professor Je-Sung Koh (corresponding author) based in Korea. The joint research team developed an artificial muscle actuator that can be applied in augmented reality (AR) goggles and naturally-fitting 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 wearable devices need to be compact and lightweight, as users wear the devices and often require mobility. The conventional actuator had certain limitations in realizing more advanced functionality, as the slim form factor and high power density would be difficult for conventional types to achieve.
The research team suggests 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 drive system with a sensing capability to develop wearable devices such as multi-focus AR goggles and naturally-fitting haptic gloves. The research team designed a lightweight, high-powered artificial muscle actuator based on a shape memory alloy (SMA), the so-called compatible amplified SMA actuator (CASA). The newly developed version is lightweight (0.22g) yet strong enough to lift a weight that is 800 times heavier than itself.
“This new actuator we are suggesting 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 providing the potential for its expanded 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 shifting is adopted to reduce vergence accommodation conflict (VAC), which can cause eyestrain for some AR goggle wearers, by directly adjusting the distance between the screen and the optical system of the prototype AR goggle based on the focus distance of the object. to be projected.
Furthermore, non-vibratory 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. The combination of multiple actuators in the limited area of the haptic device prototype also enables more expressive touch experiences.
CASA triggers an action on an object with pressure and measures the pressure without a sensor using an artificial muscle characteristic 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 that recognize expressions made by the tactile writing system and convert them into electrical signals.
1 Samsung Research, serving as Samsung Electronics’ advanced research and development center, leads the development of future technologies for the company’s Device eXperience (DX) division.