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The interface dynamics and nanoscratched mechanisms of alkanethiol self-assembled monolayers (SAM) chemisorbed on a gold surface are investigated using molecular dynamics simulation. The characteristic mechanisms mainly include the nanoscratched depths, the workpiece temperatures, the scratched speed, the SAM chain lengths, and the shapes of the indenters. The simulation results show that the disorder and the plastic mobility of SAM structures increased with increasing nanoscratched depth. The scratched forces, the potential energy, the friction force, and the friction coefficient increased with increasing scratched depth. The larger scratched depth required a larger force to overcome the resistance, which leads to the increases in the friction force. The variations of the scratched forces and the friction forces after scratching at various temperatures are very similar. An increase in the scratched force, friction force, and friction coefficient with increasing scratched speed is observed. The scratched shape after scratching is clearer for a longer SAM chain. The SAM structures are easily tilted and bent when the chain length is longer. The reaction forces after scratching using a spherical indenter are higher than those after scratching using a Vickers indenter.

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This study reports the phase detection of the two-port flexural plate wave (FPW) sensor for designing and integrating the miniature system and provides a comprehensive methodology for portable using in the biosensor applications of severe acute respiratory syndrome coronavirus (SARS-CoV). The miniature system mainly utilizes the concept of the frequency divider that involves a divider, a time-based oscillator and a gate to reduce the high frequency, and the FPW sensor is fabricated using microelectromechanical systems (MEMS) technologies for producing a potable biosensing detector. The results demonstrate that the insertion loss decreased about 1 15% dB/ C, and the phase delay was about 2.05 /(1000 cP). The phaseshift resolution was about 10 mV per degree, and the original frequency of 4.2 MHz was divided by 100 to reduce the frequency to 42 kHz. The SARS-CoV could be detected via the S protein binds to the human angiotensin-converting enzyme 2 (hACE2) as a functional receptor, which would cause the phase delay due to the combining of the antibody with the antigen. Therefore, the feasibility studies provide the information that phase detection is an appropriate low-cost technology via frequency divider for fabricating of the miniature biosensors.Index Terms-Biosensing, flexural plate wave, integrated system, phase detection, readout concept, severe acute respiratory syndrome coronavirus (SARS-CoV).