Shape memory polymers are an emerging class of smart materials that have the ability to return from a deformed temporary shape to their original permanent shape when subjected to an external stimulus such as heat, light, and a magnetic field. These polymers have recently gained substantial interest in many applications including robotics, biomedical devices, and soft electronics. In many of these applications, there is an immediate industrial need for replacing conventional triggering methods for actuating the polymers with a more efficient and flexible method. This Grant Opportunities for Academic Liaison with Industry (GOALI) grant will investigate high-intensity focused ultrasound as a novel and promising stimulus with unique capabilities to actuate the controlled shape recovery of shape memory polymers. Focused ultrasound actuates the polymer remotely and locally, is noninvasive, and is biocompatible. These properties make the methodology a superior candidate, particularly for biomedical applications. The research will be integrated into industrial practice by the industrial partner, MedShape Inc., to provide practical approaches for the fabrication of ultrasound-sensitive polymers for medical applications. MedShape Inc. will fabricate industrial shape memory polymer actuators and provide student internship opportunities. The outcomes of this research award will increase the core competencies of U.S. medical industries.
This award will support the experiments and multiscale modeling of the dynamics of shape memory polymers under high-intensity focused ultrasound fields. The research aims at filling a knowledge gap in terms of considering time-variant and nonlinear effects associated with high excitation levels in acoustic-responsive polymers. A multiphysics framework will be established to bridge the dynamical deformation mechanisms at the atomistic scale to the response of the polymer at the macroscale. This framework will then be combined with experiments to efficiently design the chemical composition and crystalline structure of ultrasound-responsive polymers, based on extrinsic length scales and intrinsic material properties. The output of the research effort will unravel the unknown mechanisms of acoustic-induced thermal actuation, by which ultrasound waves heat polymers, and help in optimizing the dynamic processes of shape fixation and recovery of shape memory polymer structures in high-intensity focused ultrasound fields. The findings will also uncover how the geometrical aspects of the additively manufactured shape memory polymers will affect the dynamics of the polymer in various ultrasound fields. In collaboration with the industrial partner, MedShape Inc., the approach developed in the research supported by this award will be utilized to design and fabricate novel ultrasound-responsive polymer-based devices with medical applications.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
