Magneto-Responsive Biopolymer Composite Based on Plasticized Poly(Butylene Succinate-Co-Butylene Adipate) and Fe₃O₄ for Flexible Actuator Application

The magnetic soft materials that can actuate in response to the external magnetic stimulus are of a high potential for the soft robotics and biomedical applications. This work reports on the new magneto-responsive materials based on the bio-based poly(butylene succinate-co-butylene adipate) (PBSA). The synthesized magnetite (Fe₃O₄) nanoparticles were incorporated into the PBSA biopolymer matrix with the Fe₃O₄ content up to 3 wt%. The addition of Fe₃O₄ enhanced the magnetic and mechanical properties of the composites; all composites exhibited only the slight increases in the storage modulus in the presence of the external magnetic flux density of 10,000 G. The 3%v/v Fe₃O₄/PBSA composite exhibited only a small increase in the storage modulus from 7.23 × 10⁵ Pa to 7.55 × 10⁵ Pa without and with the magnetic flux density 10,000 G, respectively. The slight increases observed indicate the retained and favorable material flexibility and softness favoring the magnetic actuation. For the bending performance, the largest bending distance of 15.6 mm with the response time within 10 s and the maximum magnetophoretic force of 0.14 mN under the applied low magnetic flux density of 1300 G were obtained from the composite with the Fe₃O₄ content of 3.0%v/v with the composite magnetization of 1.719 emu g^{− 1}. The fabricated soft magneto-responsive materials based on PBSA and Fe₃O₄ nanoparticle are shown here to be potential as soft magneto-responsive materials in the field of actuator such as soft robotic components.