Hand exoskeletons have significant potential in labor-intensive fields by mitigating hand grip fatigue, enhancing hand strength, and preventing injuries.However, most traditional hand exoskeletons are driven by motors whose output force is limited under constrained installation conditions. In addition, they also come with the disadvantages of high power consumption, complex and bulky assistive systems, and high instability.In this work, we develop a novel hand exoskeleton integrated with magnetorheological (MR) clutches that offers a high force-to-power ratio to improve grip endurance. The clutch features an enhanced structure design, a micro roller enhancing structure, which can significantly boost output forces. The experimental data demonstrate that the clutch can deliver a peak holding force of 380 N with a consumption of 1.48 W, yielding a force-to-power ratio of 256.75N/W, which is 2.35 times higher than the best reported actuator used for hand exoskeletons. The designed MR hand exoskeleton is highly integrated and comprises an exoskeleton frame, MR clutches, a control unit, and a battery. Evaluations through static grip endurance tests and dynamic carrying and lifting tests confirm that the MR hand exoskeleton can effectively reduce muscle fatigue, extend grip endurance, and minimize injuries. These findings highlight its strong potential for practical applications in repetitive tasks such as carrying and lifting in industrial settings.

We developed a 3D end-effector type of upper limb assistive robot, named as Assistive Robotic Arm Extender (ARAE), that provides transparency movement and adaptive arm support control to achieve home-based therapy and training in the real environment. The proposed system composes five degrees of freedom, including three active motors and two passive joints at the end-effector module. The core structure of the system is based on a parallel mechanism. The kinematic and dynamic modeling are illustrated in detail. The proposed adaptive arm support control framework calculates the compensated force based on the estimated human arm posture in 3D space. It firstly estimates human arm joint angles using two proposed methods: fixed torso and sagittal plane models without using external sensors such as IMUs, magnetic sensors, or depth cameras. The experiments were carried out to evaluate the performance of the two proposed angle estimation methods. Then, the estimated human joint angles were input into the human upper limb dynamics model to derive the required support force generated by the robot. The muscular activities were measured to evaluate the effects of the proposed framework. The obvious reduction of muscular activities was exhibited when participants were tested with the ARAE under an adaptive arm gravity compensation control framework. The overall results suggest that the ARAE system, when combined with the proposed control framework, has the potential to offer adaptive arm support. This integration could enable effective training with Activities of Daily Living (ADLs) and interaction with real environments.

A bio-inspired humanoid robot that sweats like a human is pretty gross. The University of Tokyo robot, called Kengoro, can send small amounts of water through porous metal bones to prevent its numerous motors from overheating. Dissipating heat has long been a challenge for robotics researchers. Most of the time engineers try to incorporate a fan, radiator system or heat sink into the structure somehow. The big drawback is that these extras take up valuable space.

At 5½ feet tall, its face fixed between a grin and a grimace, the humanoid robot Kengoro is something of a synthetic Arnold Schwarzenegger. That is not to say the machine, created by the University of Tokyo's JSK laboratory, is a recursive time-traveling assassin. Rather, Kengoro is a sweaty beefcake among metal bipeds. The average two-legged machine does not have Kengoro's stamina. For a svelte robot, Kengoro is strong, powered by 108 motors.

As we exercise, our bodies can produce a lot of heat as our muscles convert chemical energy into mechanical energy. To keep moving effectively during such conditions, we produce sweat to cool ourselves down. As the water in our sweat evaporates, it takes excess heat with it, allowing us to keep moving without overheating. A team from the University of Tokyo has created a robot that can exercise and cool off in a similar way, inspired by human sweat. The new robot is named Kengoro.

Robots are hailed for their intelligence and work efficiency, but excessive heating from prolonged hours of work often affects their performance. To address the heating problem faced by humanoid robots, Japanese researchers have devised an out-of-the-box solution. Using the analogy of sweating that happens in the human body as a result of continuous activity that cools the heated muscles, researchers at the University of Tokyo's JSK Lab presented a novel method at the IEEE/RSJ International Conference on Intelligent Robots and Systems held in South Korea. Their cooling solution addresses the heating problem of a musculoskeletal humanoid robot called Kengoro, which stands at 1.7 meters (5.6 feet) tall and weighs 56 kilograms (123.5 pounds). The Japanese researchers' cooling solution involves tinkering to make the robot "sweat" water straight out of its frame.

A novel design for robots allows them to "sweat", greatly improving thermal and mechanical integrity. The bot from SCHAFT was a top scorer in the DARPA Robotics Challenge Trials in 2013. The University of Tokyo's JSK Lab's Kengoro is a 1.7-meter (5.6 feet) tall, 56-kilogram (123 pounds) musculoskeletal humanoid crammed to the brim with circuit boards and 108 motors. These structural components generate a lot of heat which would constrain the bot's performance, and there wasn't much room for any cooling mechanisms. JSK lab developed Kengoro's 3-D frame to be porous, capable of maintaining a system of flowing water.

Years of evolution got something right. Scientists at the University of Tokyo found that, in trying to keep their humanoid robot cool, the most effective way to avoid overheating was to make it sweat. Kengoro is made up of 108 motors, with a frame laser sintered from aluminum, and researchers found that making the robot sweat was an effective cooling system for a bot filled to the brim with bolts. Even with the space-saving technique, the bot weighs 123 pounds and stands 5 feet 7 inches tall. "Usually the frame of a robot is only used to support forces," lead author Toyotaka Kozuki told IEEE Spectrum in an interview published Friday.

When we use our muscles, they produce heat as a byproduct. When we use them a lot, we need to actively cool them, which is why we sweat. By sweating, we pump water out of our bodies, and as that water evaporates, it cools us down. Robots, especially dynamic robots like humanoids that place near-constant high torque demands on their motors, generate enough heat that it regularly becomes a major constraint on their performance. One of the reasons that SCHAFT did so well at the DRC Trials, for example, was their fancy liquid-cooled motors that could put out lots of torque over an extended period of time without overheating.