Page 321 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

Before we build the android hand, we will first build a few manually
operated air muscle demonstration devices. The demonstration
devices allow you to become familiar with the operation and func-
tion of the air muscle, before attempting a more complex project.
Manual control of an air muscle is fine for projects needing one or
two air muscles. However, when five or six air muscles need to be
operated in sequence or unison, manual control is not practical.
Instead, we employ computer control. One may use an IBM PC or
compatible PIC microcontroller. The interface to either computer
is the same. In this chapter we will use the IBM PC. To control the
air muscle via a computer (IBM or compatible printer port)
through the PC’s parallel port adds approximately $25.00 per air
muscle to the cost.

Advantages of the air muscle

5
Light weight. Six-inch air muscle with 18" of / 32"-diameter air
tubing weighs approximately 10 g.
Contraction. Six-inch air muscle contracts approximately 1"
(about 25 percent of its length, ends not included).
300 Powerful. Generates a force of approximately 6.5 lb at 42
pounds per square inch (psi). The power-to-weight ratio can
reach 400:1.
Pliable. Soft, pliable construction and can be bent around
curved surfaces and still function properly.

Uses
The air muscle lends itself to robotics and automation. In some
applications it can replace servo motors and direct current (DC)
motors. Its unique properties—lightweight, strong, and pliable—can
be capitalized on in many applications and used to improve existing
pneumatic designs. In a nutshell, the air muscle may be used in many
applications that require linear or contractive motion. In many cases
pneumatic cylinders can be replaced.

How the air muscle works

The air muscle has a long tube constructed out of black plastic
mesh. Inside of it is a soft rubber tube. Metal clips are fastened on
each end. The plastic mesh is formed into loops on each end,
tucked into and secured by the metal clips. The loops are used for
fastening the air muscle to devices.

Team LRN
Chapter sixteen