Tag Archives: Actuator

Researcher Create More Lifelike Soft Robots That Can Mimic Biological Muscle

A group of researchers from the University of Colorado in Boulder (US) is working on the next generation of robots. Instead of the metallic droids concept, these robots are made from soft materials that are more similar to biological systems. Such soft robots hold a huge potential for future applications. They can adjust to dynamic environments and also suitable for close human interaction. Christoph Keplinger from the University of Colorado said,

We draw our inspiration from the astonishing capabilities of biological muscle,

The soft devices, including the muscle actuator, can perform a variety of tasks
The soft robots, including the muscle actuator, can perform a variety of tasks

The newly developed class of soft, electrically activated devices are capable of simulating the expansion and contraction of actual muscles. These devices can be constructed from a wide range of low-cost materials. They are able to self-sense their movements and self-heal from electrical damage.

They developed hydraulically amplified self-healing electrostatic (HASEL) actuators which eliminate the bulky, rigid pistons, valves, pumps and motors of conventional robots. The soft structures of HASEL react to applied voltage with a wide range of movement. According to the study published in the journal Science Robotics on January 5, these flexible robots can perform a variety of tasks. They can handle delicate objects like raspberry or raw egg, as well as lift heavy objects. Keplinger said,

HASEL actuators synergize the strengths of soft fluidic and soft electrostatic actuators, and thus combine versatility and performance like no other artificial muscle before,

He also added,

Just like a biological muscle, HASEL actuators can reproduce the adaptability of an octopus arm, the speed of a hummingbird and the strength of an elephant.

HASEL actuators can simulate the strength, speed, flexibility, and efficiency of biological muscle which may enable artificial muscles for human-like robots. HASEL can make next generation of prosthetic limbs more cost-effective and reliable. This is an important step forwards for soft robotics.

The team is already working on new HASEL actuators that would work with five times lower voltage levels than those described in the studies. The voltage published in the papers is similar to the low-current shock one might get from static electricity, and it’s not hazardous to humans.

The work of this researchers promises a huge improvement in the world of robotics and prosthetic limbs. Their dream is to create robotics that is lifelike. More information can be found in an article appeared in Science recently.

Researchers Developed VO2 Based MEMS Mirror Actuator That Requires Very Low Power

A joint research by the US Air Force Research Laboratory Sensors Directorate and Michigan State University have developed micro-electromechanical systems (MEMS) actuator based on smart materials, specifically vanadium dioxide (VO2). In the room temperature, Vanadium dioxide exhibits the Mott transition. It is a not-well-understood phenomenon known to occur in transition metal chalcogenides and transition metal oxides.

VO2 Based Mott - MEMS Mirror Actuator
VO2 Based Mott – MEMS Mirror Actuator

The research team was able to use VO2 thin films for making complex mirror support structures to create a programmable tilting mirror. Transition-metal oxides like VO2 require little energy to drive the transition and less than more conventional actuation technologies. This enables implementation of transition-metal oxide based MEMS in battery powered and mobile devices.

When an input voltage of 1.1V is applied, the mirror platform achieves the maximum vertical displacement of 75 microns. The average power consumption per mirror actuator is 6.5mW and the total power consumption is 26.1mW for the entire device. The Mott-MEMS actuator mirror showed vertical movements and tilt angles of 75 micrometers and 5.5 degrees, respectively.

While testing, vanadium dioxide (VO2) displayed hysteric behavior or memory effect. That means the current response to externally applied electrical force is dependent on the previous response. Such behavior will let the researchers predict its response nature for certain electrical signals and they can program the actuators to generate different types of responses.

Nelson Sepulveda, a professor of electrical and computer engineering at Michigan State University, said in a statement issued by Wright-Patterson Air Force Base,

The actuation of such devices using smart phase-change materials represents a new operating principle that enables their programming and reduces power consumption.

The study opened a new door in the development of MEMS mirror actuation technology, which could incorporate the use of the hysteresis of smart materials like VO2 for programming tilt angles and vertical displacements in MEMS mirrors. The researchers are focusing on developing programmable MEMs mirrors and improving the design to achieve more precise control and larger movements.

Flexible haptic actuators designed for wearable devices


Graham Prophet on edn-europe.com talks about a new cooperation between Kemet and Novasentis aim to develop the next generation of haptic actuators that acts as a second skin for devices.

Kemet and Novasentis, developer of haptic and sensory feedback technology for wearable devices, have announced a collaboration to develop next generation Electro-Mechanical Polymer (EMP) film based haptic actuators for wearable devices. Novasentis will provide the core technology and haptic actuator film whereas Kemet will develop the manufacturing process for the final assembly.

Flexible haptic actuators designed for wearable devices – [Link]