Abstract

The polymer coating on a Quartz Crystal Microbalance can be done using spin coating, dipping, spray coating (airbrush) and ultrasonic spray coating. Film thickness and surface morphology of the coating depend on the coating method. Using spray coating, one can control the film thickness and also the morphology by controlling the speed, polymer-solvent particle size, concentration and duration of the deposition process. This paper presents a method for monitoring the deposition of polystyrene onto the QCM sensor by using an ultrasonic atomizer system. The atomizer was working using an ultrasonic generator at 55 kHz. Theoretically, the atomizer was able to produce a mist of solvent and polymer with a diameter of around 28 microns. The system was equipped with a frequency counter which able to monitor the resonance frequency of the sensor being coated in every second with a resolution of 1 Hz. The frequency change was related to the amount of the deposited polymer and solvent on the sensor surface; it means that the deposited polymer can be measured and monitored during the coating process. The deposited polystyrene and its solvent were monitored directly by observing the frequency change of the sensor is coated. For 10 MHz sensor, the resolution was equaled to a deposited mass of 4.2ng. It means that the amount of the coating material to be deposited on the sensor surface can be controlled with high resolution. The evaporation of the solvent after coating process was also able to be monitored directly. The benefit offered by this system besides controlled mass deposited is also the simplicity of the system.

Highlights

  • Quartz Crystal Microbalance (QCM) has been used extensively for chemical sensor and biosensor.The wide range usage of the sensor was supported by the characteristic of the sensor

  • High accuracy and resolution of frequency counter resulted in higher resolution of the QCM sensor system [2]

  • We developed a coating system for the QCM sensor which can directly monitor the coating development of the QCM sensor being coated in real time

Read more

Summary

Introduction

Quartz Crystal Microbalance (QCM) has been used extensively for chemical sensor and biosensor.The wide range usage of the sensor was supported by the characteristic of the sensor. Both side of the resonator was coated with polystyrene in two different methods, i.e., spin coating for the bottom side and ultrasonically atomized spray for the upper side. The frequency counter with 1 Hz resolution which attached to the specimen table in the chamber for real-time monitoring of QCM frequency resonant during ultrasonic spray coating was a self-build.

Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.