Abstract
In the present paper, an outer frame module for micro robots is proposed and developed. The outer frame module has a feature with both structure body transmitted force and torque and actuator-control system. This module composed of two links (Link L1 and Link L2) and one hinge is made by a small molding injection machine. This hinge is called a large-deflective hinge which has large angular displacement about ±45 deg. of more than elastic region angles. As actuators at the hinge part, the relationship between current and strain of two kinds of SMA, that is, SMA coils and SMA wire is investigated. The two SMA coils were selected as actuators because of its large strain effects. In the theory, the fixed positions of two SMA coils at the hinge part is investigated and determined after analyzing the relative angular displacement between L1 and L2 and the pressure angle at the hinge part. In the experiments, the relative angular displacement between L1 and L2 is investigated, it is shown that it has an angle of more than 40 degrees.
