Summary: UCLA researchers from the Department of Bioengineering have developed a permanent fluidic magnet that maintains stable colloids for application in a variety of fields, including physiological monitoring and bioelectronics.
Background: Colloid suspensions are comprised of dispersed small solid particles in fluids. The stability of a colloid suspension depends on the interplay between the downward gravitational pull on the particles and Brownian motion, the random movement of small particles suspended in fluid. Ferrofluids are magnetic fluids that are stable colloid suspensions as long as the particles’ Brownian motion dominates the gravity forces. One drawback of Brownian motion in ferrofluids is that it leads to rapid magnetization relaxation and prohibits permanent magnetism. There are promising applications for ferrofluids in physiological measurement at the interface between electronic systems and biological tissues if this problem can be overcome.
Innovation: UCLA researchers in the Department of Bioengineering have developed a novel permanent fluidic magnet that maintains a stable suspension using non-Brownian magnetic particles. This technology consists of magnetic non-Brownian particles that are oriented in a three-dimensional magnetic network structure that is suspended in a carrier fluid. Due to this arrangement, particle Brownian motion and colloidal stability are decoupled in the system, resulting in its permanent magnetization. The device reported possesses high coercivity, remanent magnetization, and stability, making it attractive for use in fluidic magnet-based liquid bioelectronics. The system can be reconfigured to accommodate different tasks such as human-machine communication. With its innovative design and versatile applications, this technology holds significant potential for advancements in various fields, from medical devices to advanced robotics.
Potential Applications: • Biomechanical sensors • Implantable devices • Flexible electronics • Stimuli-responsive materials • Platform technology for physiological measurements • Liquid-based robotics • Wireless liquid drug delivery • Tissue engineering (e.g., blood or neural cell regeneration, collagen alignment,)
Advantages: • Stable colloid suspension • Flowability • Modular • Reconfigurability
Development-To-Date: The first demonstration of the invention is complete (10/11/2022)
Publications:
Zhao, X., Zhou, Y., Song, Y. et al. Permanent fluidic magnets for liquid bioelectronics. Nat. Mater. 23, 703–710 (2024). Permanent fluidic magnets for liquid bioelectronics
Reference: UCLA Case No. 2024-083
Lead Inventor: Jun Chen