Robot Reviews

In Japan, they don't just create robots. They make sure the designs are incorporated with a touch of flamboyance. Himawari, the prototype sunflower robot is your perfect example.

In case you didn't know, sunflowers didn't get their name from the shape of their heads, which look like caricatures of golden suns. Instead, they got it from their characteristic of following the sun wherever it was during the day. Thus, you'll see most of them, particularly during the bud stage, turned to the east in the morning (where the sun rises) and to the west in the afternoon (where the sun sets). This characteristic is called heliotropism. 

Himawari's creator, Akira Nakayasu of Kyushu University, patterned his robot's main feature from heliotropism. However, instead of following the sun, Himawari is designed to react to hand motions. To achieve this, the robot emits infrared light from numerous LEDs and captures the signals reflected from the interacting hand. The signals are then sent to an attached PC that processes the information needed to direct the servomotors in the stalk, subsequently moving the sunflower in the direction of the hand.

The sunflower's large majestic head has captured the fascination of many an artist. One of them, no less than the eccentric Vincent van Gogh. His "Still Life: Vase with Fifteen Sunflowers", one in a series of sunflower paintings, fetched a record-setting US$ 39.9 Million. Although we don't know whether Akira Nakayashu is also an eccentric, his creation is definitely a modern-day of work of art.

As the sunflower's head gracefully follows the hand, its 48 white LEDs twinkle even as other parts of the flower robot likewise move in synchrony. The motions are made possible by actuators made of shape memory alloys a.k.a. smart metals. Shape memory alloys are now commonly used in robots, like the bat robot in one of our recent posts.