Zhuang Jian, Jiao Yangbohan, Mugabo Vincent
Key Laboratory of Education Ministry for Modern Design Rotor-Bearing System, Xi'an Jiaotong University, Xi'an 710049, China; School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Key Laboratory of Education Ministry for Modern Design Rotor-Bearing System, Xi'an Jiaotong University, Xi'an 710049, China; School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Micron. 2017 Oct;101:177-185. doi: 10.1016/j.micron.2017.07.007. Epub 2017 Jul 23.
Scanning ion conductance microscopy (SICM) is a non-contact surface topography measurement technique that has been increasingly used for soft surfaces such as living biological samples. An approach-retract scanning (ARS) mode is widely used to avoid collision between the SICM probe (i.e., pipette) and an abrupt increase in sample profile. However, the redundant pipette trajectory in the ARS mode lengthens the scan time, thus reducing SICM efficiency and time resolution. To avoid this problem, a new scanning mode is discussed that adds horizontal movement at each measurement point to predict the upcoming sample topography via variation in ion current. The pipette then retracts in response to raised topography, while it raster scans flat or downhill topography. The feasibility was verified by finite element analysis and experimental tests on three kinds of soft samples: polydimethylsiloxane, mice cardiac fibroblasts, and breast cancer cells. The pixel detection frequency during imaging and the mean square error of the sample topography were compared for the two modes. The new scanning mode enhances the SICM imaging rate without loss of imaging quality or scanning stability, while it increases efficiency and time resolution. It thus has an improved performance for characterizing biological samples.
扫描离子电导显微镜（SICM）是一种非接触式表面形貌测量技术，越来越多地用于诸如活生物样品等柔软表面。进近-回缩扫描（ARS）模式被广泛用于避免SICM探针（即移液管）与样品轮廓的突然增加之间发生碰撞。然而，ARS模式中多余的移液管轨迹会延长扫描时间，从而降低SICM效率和时间分辨率。为避免此问题，本文讨论了一种新的扫描模式，该模式在每个测量点增加水平移动，以通过离子电流变化预测即将到来的样品形貌。然后，移液管会根据升高的形貌回缩，而在平坦或下坡形貌上进行光栅扫描。通过对三种柔软样品（聚二甲基硅氧烷、小鼠心脏成纤维细胞和乳腺癌细胞）进行有限元分析和实验测试，验证了该方法的可行性。比较了两种模式下成像过程中的像素检测频率和样品形貌的均方误差。新的扫描模式提高了SICM成像速率，而不会损失成像质量或扫描稳定性，同时提高了效率和时间分辨率。因此，它在表征生物样品方面具有更好的性能。
