UCLA

The magnetoelastic effect, also named as Villari effect and discovered by Italian physicist Emilio Villari in 1865, is the variation of the magnetic field of a material under mechanical stress. This effect has been traditionally observed in rigid metals and metal alloys with an externally applied magnetic field and has been overlooked in the field of soft bioelectronics for three reasons. First, the magnetization variation in the biomechanical stress range is limited. Second, the requirement of the external magnetic field induces structural complexity and bulkiness. Finally, there exists a six orders of magnitude difference in mechanical modulus between magnetoelastic metals/metal alloys and human tissue. In 2021, our lab at the University of California, Los Angeles (UCLA) discovered the giant magnetoelastic effect in a soft system, constructed with micro/nanomagnets dispersed in a silicone matrix. In conjunction with electromagnetic induction, a soft magnetoelastic generator (MEG) is engendered via a two-step conversion system. The first step involves a mechanical-to-magnetic conversion and the second step a magnetic-to-electrical conversion. Together, an MEG-based soft bioelectronics can convert mechanical motions to electricity in a self-powered working manner. The mechanical stress alters the inter-distance and intra-dipole alignment of micromagnets, thereby modifying the magnetic field generated by the soft composite. The soft magnetoelastic composite is used to develop stretchable and water-resistant generators capable of adhering conformably to human skin. These innovative devices have the potential for energy, sensing, and therapeutic applications, opening new avenues for human-body-centered applications. In this dissertation, I will provide the progressive development of MEGs as a new platform technology for assistive technologies. The forthcoming sections outline the breadth of applications that MEGs offer. Then, I will discuss in detail the approaches as the first/co-first author in devising MEG-centered assistive technologies. By combining the unique properties of MEGs with the principles of assistive technology, I have developed intelligent and self-powered solutions, tailored to the requirements of specific user groups. The adaptability, flexibility, and mechanical durability of MEGs make them ideal for creating assistive devices that can enhance mobility, accessibility, and independence for users. Last but not least, I shall explore the challenges, opportunities, and future directions for the development and integration of MEGs in assistive devices. In essence, this dissertation constitutes a substantial stride in the field of soft MEGs, ushering them into the domain of assistive technologies. It showcases the potential of these devices to revolutionize the field, enabling the development of intelligent, self-powered, and user-centric solutions that can significantly improve the quality of life for individuals in need.