An integrated platform for the capture, transport, and detection of individual superparamagnetic microbeads is described for lab-on-a-chip biomedical applications. Magnetic domain walls in magnetic tracks have previously been shown to be capable of capturing and transporting individual beads through a fluid at high speeds. Here it is shown that the strong magnetostatic interaction between a bead and a domain wall leads to a distinct magneto-mechanical resonance that reflects the susceptibility and hydrodynamic size of the trapped bead. Numerical and analytical modeling is used to quantitatively explain this resonance, and the magneto-mechanical resonant response under sinusoidal drive is experimentally characterized both optically and electrically. The observed bead resonance presents a new mechanism for microbead sensing and metrology. The dual functionality of domain walls as both bead carriers and sensors is a promising platform for the development of labon-a-bead technologies.
The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. Experiments show that nanotrack-guided domain walls can propel individual trapped beads through an aqueous medium at speeds approaching 1000 μm/s, 10 to 100 times faster than through any previously demonstrated mechanism.
The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. A combination of micromagnetic modeling and numerical calculation is used to determine the strength of bead-domain wall interaction for a range of track geometries and bead sizes. The maximum domain wall velocity for continuous bead transport is predicted from these results and shown to be supported by experimental measurements. Enhancement of the maximum velocity by appropriate material selection or field application is demonstrated and an analysis of the source of statistical variation is presented. Finally, the dynamics of beaddomain wall interaction and bead transport above the maximum domain wall velocity for continuous domain wall-mediated bead transport is characterized.Submitted to Phys. Rev. B 2
Global megatrends are re-shaping the world economic order. From urbanisation, to the rise of the global middle classes, ageing population and technological trends, these changes all pose major implications for the built environment and demand for housing in the short-and long-term. According to the latest projections by the United Nations, the world's population is expected to grow by 2.9 billion in the next 33 years and potentially another three billion by the end of the century. At the same time, the move towards cities is expected to continue, driven by economic, climate change and conflict motivations, as a result of which, 80-90% of people are expected to live in cities by 2100 (United Nations 2017).As population growth and urbanisation continue, cities are faced with a number of challenges such as air pollution, congestion, social issues and pressure on housing markets. The pressure on housing markets can be analysed from different perspectives. Looking at the issue from a financial market perspective, the issue of financial market stability is a key element. However, when addressing the issue from a social and economic perspective, the focus lies more on risks like affordability, city competitiveness and social segregation.This paper examines the role of urbanisation and current megatrends we are seeing in today's world, as well as the implications of the growing popularity of residential property as a real estate investment class, on the housing market in major cities. Unintended consequences of rising house prices, housing shortages and unaffordability are explored followed by potential solutions. In order for cities to be successful, careful consideration needs to be given to managing and resolving housing affordability challenges. This is a step towards creating a balanced housing
Magnetic domain walls in ferromagnetic tracks can be used to trap and transport superparamagnetic beads for lab-on-a-chip applications. Here it is shown that the magnetostatic binding between a domain wall and a superparamagnetic bead suspended in a host fluid leads to a distinct magneto-mechanical resonance under application of a sinusoidal driving field. The characteristic resonant frequency depends on the ratio of the magnetostatic binding force to the viscous drag on the bead. This resonance has been experimentally detected for a single trapped superparamagnetic bead using an optical detection technique.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.