Open Source Quartz Crystal Microbalance with dissipation monitoring

C.A. MISTA, M. ZALAZAR, M. MARTINA, A. PEÑA, J.M. RETA

Journal of Physics: Conference Series

IOP Publising

Año: 2016 vol. 705

The dissipation factor and subsequently the characterization of the viscoelasticity ofdeposition films have become crucial for the study of biomolecular adsorption. Most of thecommercial quartz crystal microbalance (QCM) systems offer this feature, but it has not beenincorporated in open source systems. This article describes the design, construction, andsimulation of an open source QCM module for measuring dissipation factor. The moduleincludes two blocks: switch and envelope detector. The switch rapidly disrupts the excitationof the crystal, and connects the output to the envelope detector which demodulates theamplitude of the signal. Damped sinusoidal exponential signals with different time constantwere used for simulating viscosity interfaces. The incorporation of few elements facilitated adouble-faced PCB design with reduced dimensions. The results from simulation show that thesystem has a good performance in the range of the biomolecular processes; greater relativeerror are observed for time constant lower than 1 us. In conclusion, a dissipation module hasbeen developed for calculate dissipation factor using QCM, which is compact and shows greatperformance for use in biomolecular adsorption.