Towards Portable MEMS Oscillators for Sensing Nanoparticles

Abstract

This paper reports on the design, and implementation of piezoelectric-on-silicon MEMS resonators installed within a portable experimental setup for sensing nanoparticles in a laboratory environment. MEMS oscillators with a center frequency of approximately 5.999 MHz are employed for sensing 50 nm size-selected silver nanoparticles generated in the laboratory. The same experimental setup is then assembled to sense indoor particles that are present in the laboratory environment. The challenges associated with particle deposition as a result of assembling the portable experimental setup is highlighted. Furthermore, the MEMS oscillators demonstrate that the total mass of silver nanoparticles deposited onto the MEMS resonator surface using the inertial impaction technique-based experimental setup is approximately 7.993 nanograms. The total indoor particle mass accumulated on the MEMS resonator surface is estimated to be approximately 1.732 nanograms and 26.9 picograms for two different runs. The frequency resolution of the MEMS oscillator is estimated to be approximately 32 ppb and, consequently, the minimum detectable particle mass is approximately 60 femtograms for a 9.2 s integration time.

Nanoscale mass measurement based on suspended graphene

“…The linear equation (the red line in figure 4(c)) is ω 2D = −69.8 ε + 2679.3. Such sensitivity is comparable to that of MEMS oscillators [2], demonstrating its potential for nanomass measurement.…”

“…The demand for small mass measurement has led to the development of sophisticated microstructure designs with ultrahigh sensitivity. Current technology mainly focuses on MEMS sensors, and their basic principle is the measurement of the resonance frequency shift due to the added mass on the cantilever surface [1][2][3][4][5][6][7]. However, the structure suffers from the complex fabrication process of cantilever transducers with piezoelectric actuators and the sophisticated equipment setup required [8].…”