Friday, April 06, 2007

Shadow Robot Hand

The Shadow robot hand is considered as one of the most advance robot hand in the world. Currently it can handle up to 24 types of movement which makes it a perfect solution for the disabled. It can hold a light bulb or a tomato, it also can write using a pen. In general, it is very skillful in physical movement or so called dexterous for such an artificial hand. By using 40 integrated air muscles, the hand can grasp soft and fragile object. The air muscle is a small actuator which is powerful and easily controllable. It behaves in a very similar way to a biological muscle. When actuated with a supply of compressed air, they contracted by up to 40% of its' original length. The force it provides decreases as it contracts and the first few percent of the contraction is very powerful. It also can be fitted with touch sensor at the fingertips which provide sufficient sensing ability to detect event a small coin. These air muscles provide the hand with many compliant movements. Following the biologically-inspired design principle, tendons couple the air muscles to the joints. Integrated electronics at the base of the hand system drive the pneumatic valves for each muscle and also manage corresponding muscle pressure sensors. Three modes of actuation are used in the Hand system. An opposing pair of muscles permits full control and variable compliance of the movement for most joints. Conditionally-coupled drive is used for the Middle and Distal phalanges of the fingers to produce human movement characteristics. The form factor of the hand is that of a typical human male, and the weight is around 3.9 kg, which is quite heavy for normal user. This is because the hand is a combination of metal and plastic. Currently it is being used mainly for researching purpose however, applying this type of hand into rehabilitation and assistive technology is a a very promising possibility in the future. References: The Shadow Robot Hand U037846R - Phan Tien Khoi


Anonymous said...

This is definitely another "think out of the box" concept. Instead of using motors as prime mover in the robotic arm, now contraction of air can also be another method.

Tng Thomson U046231A

Anonymous said...

Whoah! I must say that to be able to mimic the contraction of muscles is a break through.

The idea of learning from nature time and again proves to work well for different problems faced. Just like the use of evolutionary algorithm in solving problems which mimics the evolutionary nature of "survival-of-the-fittest".

Hope that this invention would one day be able to help people with disabilities lead a normal life again.

Ng Zhihong U036095H

Jefferson U045932H said...

In my opinion, the invention of such a robotic arm with movements caused by systems modelled after that of nature, will pave the way for the invention of a true humanoid.

For now of course, such applications might prove useful for the disabled and operations that require much care in handling.

However, I am concerned about how such devices are powered, assuming that it is being used on disabled people. Are these physically challenged people required to carry a huge pack of battery on their back as well?

Comments? =p

Anonymous said...

This is one of the most advanced and sensitive robotic limb that men have developed up to date. Having a large range of possible movements and sensitive control even capable of writing, this invention paves the way for future advancement in robotic arms for disabled. In my opinion, the next step would be to integrate biotechnology together with robotics to enable disabled people better control of such robotic arms. In fact, I found this article where a man can control his robotic arms with his mind. The theory is to use electrical signal generated by contraction of muscle to communicate with a computer attached to robotic arm. (

Su Shiyan

Industry said...

It is really not easy for robot hand to handle fragile objects.

However, looking at the number of air muscles attached to the robot hand, will it be too complex for the user to control the motion of the fingers?

Also, 3.9kg is definitely too heavy for normal users. Light but tough material will surely replace steel in the future, but then the cost again may increase and even become unaffordable.

Xue Chao

Industry said...

Is the shadow robot hand able to be control by human brain?

I think that it is really a great success when robotic arm that can be controlled by human's brain is invented. This will give the disabled a chance in doing many works easily.

It is really amazing that this shadow robot hand utilize the contraction of air to mimic the motion of biological muscle. This method might can be used to imitate the function of other human organ.

Yong See Wei U048661X

Assistive said...

The solution for energy part is quite simple i think. We can use some kind of solar rechargeable battery, it will charge whenever the user is under the sun and the battery will provide power for the other time.
Human can also control the hand using the brain by sending neural signal to the Controller Area Network(CAN) of the hand.
The weight of the hand is also a problem but it can be solved by using lighter material.

Phan Tien Khoi

Anonymous said...

I have read about this before. This hand is a great but a major obstacle in the usage of such device in mainstream robotics is the air muscle used to control the motion. This hand consists of around 40 such muscles each of which is actuated by a supply of compressed air. The main problem then shift to the control of the passage of the compressed air.
This sure is a good invention in field of robotics taking things away from the electronics, but there are still lot of major issues involved.

Nitin Batra - U048708Y

Aumkar said...
This comment has been removed by the author.
Aumkar said...

why can't springs attached to a servo motor be used in this case. i'm just a student n i don kno much bout this but i'm intrested in such ideas. according to me motors cn immitate this more accurately as we cn have a system which expands n contracts simultaneously. lyk in reality for any movement of our hand, if some muscles contract den others expand restricting da movement.