Magnetic surfaces for the controlled manipulation of superparamagnetic microbeads

以功能化表面为标记的超顺磁性微球的操纵用于单分子研究、细胞操纵以及检测液体环境中的化学或生物物种是该研究项目的重点。在该项目中，将探索超顺磁珠在功能化磁性表面上移动的基本原理。作为操纵珠子的基础，将研究以阵列元件的形式形成微光刻图案的磁性表面，以形成相互连接的磁性网络。单个珠子的传输由微磁性物体执行，例如带电磁畴壁或可切换磁化结构。在该项目中，将研究在可变多轴磁场方案的帮助下微珠长磁结构的受控运动。人们正在探索不同的方法来传输液体悬浮液中的超顺磁性粒子。此外，还将通过施加具有不同频率分量的时间和角度变化的磁场来利用流体动力效应。利用互补原位磁显微镜和亮场光学显微镜直接分析了微珠的横向分布和相应的运动。调查将得到深度模拟的支持。这项研究将开辟新的方法来横向操纵标记的生物物体，促进微流体环境中粒子在实质性距离上的受控运动，并以这种方式为在集成的无流动芯片实验室设备中操纵和分离生物物体提供基础。

The manipulation of superparamagnetic microbeads withfunctionalized surfaces as labels for single-molecule studies, for cellmanipulation, and detection of chemical or biological species in liquidenvironments are in the focus of the research project. Within theproject the fundamentals for the movement of superparamagneticbeads on functionalized magnetic surfaces will be explored. As abasis for the manipulation of beads, micro-lithographically patternedmagnetic surfaces in the form of array elements creating aninterconnecting magnetic network will be investigated. The transportof individual beads is performed by micro-magnetic objects such ascharged magnetic domain walls or switchable magnetizationstructures. Within the project the controlled movement of microbeadsalong magnetic structures with the help of variable multi-axismagnetic field protocols will be investigated. Different approaches arebeing explored for the transport of superparamagnetic particles inliquid suspensions. Moreover, hydrodynamic effects will be utilized byapplying temporal and angle varying magnetic fields with differentfrequency components. The lateral distribution of the magneticpatterns and the corresponding motion of the microbeads areanalyzed directly by complementary in-situ magnetic and bright-fieldoptical microscopy. The investigations will be supported by in depthsimulations. The research will open up new ways to laterallymanipulate marked biological objects, to facilitate a controlledmovement of particles in microfluidic environments over substantialdistances, and in that way provide the foundations for themanipulation and separation of biological objects in integratedflowless lab-on-chip devices.