**2.1 Applied android robot**

The presented android robot hand is made for an android robot EveR 3. EveR 3 is the latest model of EveR 1 which was the first android robot in Korea. It was designed for stage performances as an actress. Because this android robot was designed as an actress, it has an elegant appearance and delicate body which can express human like motions. To make human like motions, it has 41 D.O.F (9 D.O.F in face, 22 D.O.F in body, 10 D.O.F in both hands) and its height is 165cm, weight is 55kg. It can move on the stage by two wheeled 82 The Future of Humanoid Robots – Research and Applications

it can be used to humanoid robot not android robot (Kenji KANEKO. et al., 2007). The HONDA ASIMO is the most well-known humanoid robot in the world and its hand shape is like human. Its appearance and size is like human and all devices are included in hand but it has only 1 D.O.F, so it is impossible to express variable gestures (K. hirai. et al., 1998) (H. Hirose. et al., 2001). N.Dechev used spring, links and ball nut joint to make multi fingered prosthetic hand. This hand can passive adaptive grasp by using only one actuator and it has human like shape, 5 fingers but it can't express variable motions because there is only one active joint. This hand shows possibility that prosthetic hands can be applied to human like robot (N. Dechev. et al., 2000). Many of exist hands used motors as actuators but Feifei Zhao used pneumatic type actuators. This hand was made of rubber tube, so there are no links or wires and the structure is so simple. However, this hand can't make gesture of human finger

The many existing researches of human like hands can be applied to humanoid robots but not matched to android robots. An android robot is one of humanoid robots but its appearance is more similar to human appearance than appearance of humanoid robot. When the android robot is designed, uncanny-vally must be concerned, in particular (Shimada M. et al., 2009). In this reason, the hand of an android required the nearest appearance to human hand than existing variable human like hands and the design is more difficult than one of humanoid hand. There are three required factors to the design of an android robot hands. Firstly, the size is very important, because it must be matched to whole body in proportion. It can be hard to make small size hand due to its complexity, but if the proportion is contrary to human body, it can look ugly. Secondly, even if the size of hand is satisfied, shape must be concerned. Most of humanoid robot hands satisfy the size policy, but the shape is not curved surface like human hand. Mechanical parts are generally angulate, so the space which can be used is narrow and this makes the design of an android robot hand hard. Thirdly, android robot hands need an artificial skin. The artificial skin is major difference between humanoid robot hands and android robot hands. The artificial skins which is used to android robot hands need human like touch, color and flexibility for

In this research, an android robot hand for an android robot EveR 3 is presented. The EveR 3 is an android robot for stage performances as an actress, so the hand of EveR 3 was made for variable gestures as acting not grasping. This hand has five fingers with 5 D.O.F and artificial skin. DC motors and screw-nut are used as actuators and the hand is driven by links. The shape is based on 3D model which was made by scanning data from real human. The artificial skin was made by silicon complex and its shape was also based on 3D model,

The presented android robot hand is made for an android robot EveR 3. EveR 3 is the latest model of EveR 1 which was the first android robot in Korea. It was designed for stage performances as an actress. Because this android robot was designed as an actress, it has an elegant appearance and delicate body which can express human like motions. To make human like motions, it has 41 D.O.F (9 D.O.F in face, 22 D.O.F in body, 10 D.O.F in both hands) and its height is 165cm, weight is 55kg. It can move on the stage by two wheeled

and its shape is different to human hand (Feifei Zhao. et al., 2006).

so its appearance is very similar to human hand.

driving.

**2. Design policies** 

**2.1 Applied android robot** 

mobile lower body and was controlled by wireless LAN. Fig.1 shows an android robot EveR 3 with skin, dress and mechanical drawing. Why this robot was made as a woman is to hide the mobile lower body. As an actress, moving on the stage is necessity, but its appearance is different to humans one, so we can hide this parts with long skirt and to wear a skirt, the woman robot is chosen not a man. There is already an android robot can walk, but it is not enough to fast, stable moving (Shin'ichiro Nakaoka. et al., 2009) (Kenji KANEKO. et al., 2009). To make a woman android robot is more difficult than a man android robot, because it has more curved body, narrow space and especially it is more sensitive in appearance. This android robot EveR 3 is based on Korean young woman. To play emotional acting, it has face which has 9 D.O.F and an artificial skin to make expressions. The full body was made by 3D data which is from real human scanning data and this data is also used to make hand, skin. The hand is designed by using this data, so the size and shape are decided from this reference. The artificial skin was also made by this data but little bit different, because the skin design needs making mold. To make mold for an artificial skin, RP (Rapid prototype) mock up was made from 3D data and the mold was made by using mock up. Silicon complex is used as an artificial skin. There are many materials which are reviewed for an artificial skin, but why silicon complex is selected is its characteristics are most like to human skin. The appearance is the most important factor to android robots, so these are design policies for hands.

Fig. 1. The android robot EveR 3 and its mechanical drawing.

Design of 5 D.O.F Robot Hand with an Artificial Skin for an Android Robot 85

The consideration of shape of an android robot hand is as important as one of its size. There are many humanoid robot hands whose size satisfy human like size, because humanoid robots are designed as real human size. However, most of their designs are not like real human hand especially shape. Even if humanoid robots have similar appearance to human, its design is based on robot basically, so shape of human is curved but one of humanoid robots is angulate (AKACHI K. et al., 2005) (Ill-Woo Park. et al., 2005) (Jun-Ho Oh. et al., 2006). The android robot hand should have curved design and it make hard to design, because most of mechanical parts are angulate, so the space which can be used is very narrow. To design human like curved shape, 3D scanned hand data which was already mentioned was used. There is consideration to use that data. The shape of this data is full straightened, so it is hard to know the shape when the finger bended. Some processing was applied to original data to make bended shape by 3D graphics program (Maya). Fig. 3 shows variable shape of finger to check. From these processes, the nearest reference 3D data

Total length 168 mm (from fingertip to wrist joint) Width 80 mm (when thumb finger is bended)

Index finger 37/23/ 18 mm (1st, 2nd, 3rd joint) Middle finger 40/28/18 mm (1st, 2nd, 3rd joint) Ring finger 36/25/18 mm (1st, 2nd, 3rd joint) Little finger 26/18/15 mm (1st, 2nd, 3rd joint) Thumb finger 32/18 mm (1st, 2nd, 3rd joint)

Thickness (Palm) 27 mm Weight 450 g

Table 1. The pamameters of developed android hand.

to real human hand can be obtained.

Fig. 3. The handled 3D data to check shape by graphics program.

**2.2.2 Shape** 
