Impedance feedback control for scanning electrochemical microscopy
Impedance feedback control for scanning electrochemical microscopy
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DOI：
10.1021/ac010581q
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发表时间：
2001-10-15
影响因子：
7.4
通讯作者：
Wipf, DO
中科院分区：
文献类型：
--
作者：
Alpuche-Aviles, MA;Wipf, DO
本文提出了一种基于探针阻抗与探针-基底间距关系的扫描电化学显微镜定距成像方法。通过在头端和辅助电极之间施加高频交流偏压来监测头端阻抗。高频交流电流很容易从直流电平法拉第电化学分离与一个简单的RC滤波器，它允许在反馈或生成/收集实验期间的阻抗测量。通过采用基于压电的反馈控制器，我们能够将阻抗保持在恒定值，从而保持恒定的尖端-基板分离。应用该方法的反馈和产生/收集实验与尖端电极小到2妈妈。
A new constant-distance imaging method based on the relationship between tip impedance and tip-substrate separation has been developed for the scanning electrochemical microscope. The tip impedance is monitored by application of a high-frequency ac voltage bias between the tip and auxiliary electrode. The high-frequency ac current is easily separated from the dc-level faradaic electrochemistry with a simple RC filter, which allows impedance measurements during feedback or generation/collection experiments. By employing a piezo-based feedback controller, we are able to maintain the impedance at a constant value and, thus, maintain a constant tip-substrate separation. Application of the method to feedback and generation/collection experiments with tip electrodes as small as 2 mum is presented.