**3.2. Implementation of artificial skin on KASPAR**

Despite the other two robot, that have an iconic appearance, KASPAR has a more human-like appearance, in fact in order to have a "natural" shape a child-sized mannequin was used as a basis and the legs, torso and the hands were kept. In order to invite children to touch the hands (which is more like touching a doll), the maintenance of human-like appearance has been an important parameter that has been kept under consideration in the covering process. For this purpose the hands have been covered with coloured foam silicone rubber (it has been

**Figure 11.** Calculated variations of C1 and C2 due to a fixed pressure applied by the probe along different positions of the straight line of measurement

(a) (b) (c)

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(a) (b)

(c)

(d) (e)

**Figure 11.** Calculated variations of C1 and C2 due to a fixed pressure applied by the probe along

different positions of the straight line of measurement

**Figure 12.** The process steps for iCub forearm: two covers are needed which are mounted together on the robot forearm.

**Figure 13.** The process steps for iCub upper arm: two covers are needed which are mounted together on the robot upper arm.

14 Will-be-set-by-IN-TECH 198 Smart Actuation and Sensing Systems – Recent Advances and Future Challenges

**Figure 15.** The process steps for iCub Torso

obtained adding color pigments to the rubber mixture). Furthermore it has been decided to not cover the silicone rubber substrate with ground plane (the KASPAR parts come in contact only with human being that constitute the ground plane during tactile contact). The hands have been scanned with a laser scanner and completely rebuild by a 3D printer in order to have the housing for the electronics (see figures 16(a) and 16(b)); The procedure used was the same explained before for the iCub parts. In figure 16(d) the final result for KASPAR hands is shown. For the other parts (cheeks, torso, upperarms and feet) we didn't take in consideration the human-like appearance because this parts, in the final setup of KASPAR, are covered by clothes. For the upper arms a cover with the housing for the electronics was build by a 3D printer and the patch was covered by a neoprene substrate. For the cheeks, torso and the feet it has not been possible to rebuild the part with the 3D printer (more expensive), so Artificial Skin patches have been applied on the puppet surfaces by glue. In total on KASPAR there are 12 MTB boards and 68 triangles that corresponds to 1128 contact point.

#### **3.3. Implementation on NAO**

For NAO the goal was to sensorize the forearms and the upper arms. Therefore, we designed 6 covers (2 for each forearm and 1 for each upper arm) to mount over the robot structural covers as for the iCub palm.

Fig. 18 shows the steps to cover NAO's forearm with skin. In total NAO has 18 triangles that correspond to 216 contact points for each lower arm and 9 triangles that correspond to 108 contact points for each upper arm.

#### 198 Smart Actuation and Sensing Systems – Recent Advances and Future Challenges Large Scale Capacitive Skin for Robots <sup>15</sup> Large Scale Capacitive Skin for Robots 199

(a) (b) (c)

14 Will-be-set-by-IN-TECH

(a) (b) (c)

obtained adding color pigments to the rubber mixture). Furthermore it has been decided to not cover the silicone rubber substrate with ground plane (the KASPAR parts come in contact only with human being that constitute the ground plane during tactile contact). The hands have been scanned with a laser scanner and completely rebuild by a 3D printer in order to have the housing for the electronics (see figures 16(a) and 16(b)); The procedure used was the same explained before for the iCub parts. In figure 16(d) the final result for KASPAR hands is shown. For the other parts (cheeks, torso, upperarms and feet) we didn't take in consideration the human-like appearance because this parts, in the final setup of KASPAR, are covered by clothes. For the upper arms a cover with the housing for the electronics was build by a 3D printer and the patch was covered by a neoprene substrate. For the cheeks, torso and the feet it has not been possible to rebuild the part with the 3D printer (more expensive), so Artificial Skin patches have been applied on the puppet surfaces by glue. In total on KASPAR there are

For NAO the goal was to sensorize the forearms and the upper arms. Therefore, we designed 6 covers (2 for each forearm and 1 for each upper arm) to mount over the robot structural

Fig. 18 shows the steps to cover NAO's forearm with skin. In total NAO has 18 triangles that correspond to 216 contact points for each lower arm and 9 triangles that correspond to 108

12 MTB boards and 68 triangles that corresponds to 1128 contact point.

**Figure 14.** The covers of iCub arms covered with conductive lycra

**Figure 15.** The process steps for iCub Torso

**3.3. Implementation on NAO**

contact points for each upper arm.

covers as for the iCub palm.

(d)

**Figure 16.** The process steps for KASPAR hands

**Figure 17.** NAO with his forearms covered with the artificial skin.

16 Will-be-set-by-IN-TECH 200 Smart Actuation and Sensing Systems – Recent Advances and Future Challenges

**Figure 18. The steps for implementing the skin on NAO's hands.** (a) The two parts of the cover for NAO's forearm. (b) The triangles for one half of the forearm. (c) The PCBs are glued to the cover. (d) The cover with the PCBs. (e) The silicone foam has been molded onto the forearm. (e) The final result.
