PURPOSE: To develop a bidirectional reversible change by compounding two kinds of shape memory resins having different glass transition temps. to allow the recovery forces thereof to compete with each other.
CONSTITUTION: Two kinds of shape memory resin molded bodies different in glass transition temp. molded mutually symmetrically in a circular arc shape are bonded to be compounded in such a state that the recovery forces thereof compete with each other and a bidirectional reversible change is developed by the recovery forces returned to respective memory shapes within two different temp. regions. For example, in a shape memory resin molded body compounded test piece composed of a resin A/B combination, when a tendency returned to the memory shape of the molded body A according to temp. is strong, the test piece is deformed so as to warp upwardly; whereas, when a tendency returned to the memory shape of the molded body B is strong, the test piece is deformed so as to warp downwardly.