Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor
Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor
复制标题
DOI：
10.3762/bjnano.7.96
复制
发表时间：
2016-07-18
影响因子：
3.1
通讯作者：
Muehl, Thomas
中科院分区：
文献类型：
--
作者：
Koerner, Julia;Reiche, Christopher F.;Muehl, Thomas
悬臂梁磁强计是一种用于研究磁性纳米颗粒的测量技术。随着样本量的减少，信号强度显著降低，需要技术的进步。超薄和细长的杠杆可以解决这一挑战，但会导致检测的复杂性增加。我们提出了一种基于微米和纳米尺寸的悬臂梁的共共振耦合的方法。通过两个子系统的共振频率的匹配，我们诱导的两个悬臂梁的振荡之间的强烈的相互作用，允许检测灵敏的纳米悬臂梁和外部影响的微悬臂梁的振幅响应曲线之间的相互作用。在我们的磁性测量实验中，我们使用了铁填充的碳纳米管同时作为纳米悬臂和磁性样品。测量结果显示，与使用类似纳米磁体的传统悬臂梁磁力测量实验相比，常用的频移信号增强了五个数量级。通过这个实验，我们不仅展示了我们的传感器设计的功能，而且还展示了它的潜力，非常灵敏的磁力测量，同时保持一个简单的振荡检测与传统的微悬臂梁设置。
Cantilever magnetometry is a measurement technique used to study magnetic nanoparticles. With decreasing sample size, the signal strength is significantly reduced, requiring advances of the technique. Ultrathin and slender cantilevers can address this challenge but lead to increased complexity of detection. We present an approach based on the co-resonant coupling of a micro- and a nanometer-sized cantilever. Via matching of the resonance frequencies of the two subsystems we induce a strong interplay between the oscillations of the two cantilevers, allowing for a detection of interactions between the sensitive nanocantilever and external influences in the amplitude response curve of the microcantilever. In our magnetometry experiment we used an iron-filled carbon nanotube acting simultaneously as nanocantilever and magnetic sample. Measurements revealed an enhancement of the commonly used frequency shift signal by five orders of magnitude compared to conventional cantilever magnetometry experiments with similar nanomagnets. With this experiment we do not only demonstrate the functionality of our sensor design but also its potential for very sensitive magnetometry measurements while maintaining a facile oscillation detection with a conventional microcantilever setup.