Kageshima Masami, Chikamoto Takuma, Ogawa Tatsuya, Hirata Yoshiki, Inoue Takahito, Naitoh Yoshitaka, Li Yan Jun, Sugawara Yasuhiro
Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Rev Sci Instrum. 2009 Feb;80(2):023705. doi: 10.1063/1.3080557.
In order to probe dynamical properties of mesoscopic soft matter systems such as polymers, structured liquid, etc., a new atomic force microscopy apparatus with a wide-band magnetic cantilever excitation system was developed. Constant-current driving of an electromagnet up to 1 MHz was implemented with a closed-loop driver circuit. Transfer function of a commercial cantilever attached with a magnetic particle was measured in a frequency range of 1-1000 kHz in distilled water. Effects of the laser spot position, distribution of the force exerted on the cantilever, and difference in the detection scheme on the obtained transfer function are discussed in comparison with theoretical predictions by other research groups. A preliminary result of viscoelasticity spectrum measurement of a single dextran chain is shown and is compared with a recent theoretical calculation.
为了探究诸如聚合物、结构化液体等介观软物质系统的动力学性质，开发了一种带有宽带磁悬臂激发系统的新型原子力显微镜装置。利用闭环驱动电路实现了高达1MHz的电磁铁恒流驱动。在蒸馏水中，对附着有磁性颗粒的商用悬臂的传递函数在1 - 1000kHz频率范围内进行了测量。与其他研究小组的理论预测相比较，讨论了激光光斑位置、施加在悬臂上的力的分布以及检测方案的差异对所获得传递函数的影响。展示了单个右旋糖酐链粘弹性谱测量的初步结果，并与最近的理论计算进行了比较。
