Multi-objective Optimal Design of High Frequency Probe for Scanning Ion Conductance Microscopy

Scanning ion conductance microscopy（SICM） is an emerging non-destructive surface topography characterization apparatus with nanoscale resolution. However, the low regulating frequency of probe in most existing modulated current based SICM systems increases the system noise, and has difficulty in imaging sample surface with steep height changes. In order to enable SICM to have the capability of imaging surfaces with steep height changes, a novel probe that can be used in the modulated current based bopping mode is designed. The design relies on two piezoelectric ceramics with different travels to separate position adjustment and probe frequency regulation in the Z direction. To fiarther improve the resonant frequency of the probe, the material and the key dimensions for each component of the probe are optimized based on the multi-objective optimization method and the finite element analysis. The optimal design has a resonant frequency of above 10 kHz. To validate the rationality of the designed probe, microstructured grating samples are imaged using the homebuilt modulated current based SICM system. The experimental results indicate that the designed high frequency probe can effectively reduce the spike noise by 26% in the average number of spike noise. The proposed design provides a feasible solution for improving the imaging quality of the existing SICM systems which normally use ordinary probes with relatively low regulating frequency.

Automated Calibration of RF On-Wafer Probing and Evaluation of Probe Misalignment Effects Using a Desktop Micro-Factory

A fully automatic setup for on-wafer contact probing will be presented. This setup consists of six automatable nano positioning axes used as tool holder and a sample holder. With this setup a fully automatic one-port SOL calibration for a Vector Network Analyzer is done. Furthermore a fully automated on-wafer contact probing is performed. Afterwards, the effects of a misalignment of the three tips of a GSG-probe are examined. Additionally the error on the calibration is calculated to determine its effect on the measurement. The results show, that a misalignment of the probe has a high impact on the measurement of the VNA. Hence a fully automated on-wafer probing presented in this paper is a good way to detect these misalignments and correct them if necessary.

The value of intraoperative ultrasonography in the operative project of hepatopancreatobiliary

Objective: To explore the reference value of intraoperative ultrasonography in the operative procedure and post- operative treatment with relation to hepatopancreatobiliary surgery. Methods: 103 cases of hepatopancreatobiliary operations were collected in our hospital from January 1996 to October 2005, in which 68 cases were males and the others were females, age ranged from 45 to 76 years. Hepatocellular carcinoma were 26 cases, gallbladder carcinoma were 5 cases, cholangio- carcinoma were 6 cases, pancreatic carcinoma were 10 cases and other 56 cases were gall stone and/or choledocholithiasis. Intraoperative ultrasonography with high frequency probe was used in all cases. Results: Some minimal occult focuses was found by intraoperative ultrasonography. We found vascular tumor thrombosis in 70% cases of hepatocellular carcinomas. One case was diagnosed as pancreatic carcinoma before operation and found choledochal tract dilatation concurrently with cholangitis by intraoperative ultrasonography. Eight cases of gallstones with no choledochal stones before operation were found by intraoperative ultrasonography that stone lain in low segment of common bile duct. Conclusion: The image data of high quality obtained by intraoperative ultrasonography could not only direct our more proper operative practice but also favor us to make more reasonable postoperative treatment plan.