Partially integrated cantilever-based airborne nanoparticle detector for continuous carbon aerosol mass concentration monitoring

Abstract

Abstract. The performance of a low-cost partially integrated cantilever-based airborne nanoparticle (NP) detector (CANTOR-1) is evaluated in terms of its real-time measurement and robustness. The device is used for direct reading of exposure to airborne carbon engineered nanoparticles (ENPs) in indoor workplaces. As the main components, a miniaturized electrostatic aerosol sampler and a piezoresistive resonant silicon cantilever mass sensor are employed to collect the ENPs from the air stream to the cantilever surfaces and to measure their mass concentration, respectively. Moreover, to realize a real-time measurement, a frequency tracking system based on a phase-locked loop (PLL) is built and integrated into the device. Long-term ENP exposure and a wet ultrasonic cleaning method are demonstrated to estimate the limitation and extend the operating lifetime of the developed device, respectively. By means of the device calibrations performed with a standard ENP monitoring instrument of a fast mobility particle sizer (FMPS, TSI 3091), a measurement precision of ENP mass concentrations of < 55 % and a limit of detection (LOD) of < 25 µg m −3 are obtained.

Handheld personal airborne nanoparticle detector based on microelectromechanical silicon resonant cantilever

“…Real NPs can be detected using mass detectors based on micro/nanoelectromechanical systems (M/NEMS) which in addition offer the necessary potential of miniaturization and cost-effective batch fabrication. Indeed, most of the currently introduced M/NEMS-based NP mass detectors still need to be operated at high flow velocity using a pump and characterized with external bulky, heavy, and vacuum tools [10][11][12][13][14][15][16]. In contrast, our second generation of a fully integrated cantilever-based airborne NP detector (CANTOR-2) developed in this work has small size and low weight.…”

“…The CANTOR-2 is an enhanced version of our previously developed cantilever-based airborne nanoparticle detector (CANTOR-1), which was still in a partially integrated system using a cylindrical electrophoretic NP sampler head, successfully detecting 20 nm carbon ENPs in off-line [14] and real-time measurements [15]. In this novel device, the NP sampler head has been improved in terms of its design and functionality.…”

“…7(a). The generation of stable test aerosols is started by nebulizing a suspension of ENPs in a solution of water/ethanol or water/isobutanol using a constant output atomizer (TSI 3076, TSI Inc.) [14,15]. Inside the atomizer, the incoming compressed air swells through an orifice forming a high-velocity jet.…”

Transferable micromachined piezoresistive force sensor with integrated double-meander-spring system

“…Fine tuning during measurement of very small forces may be problematic since the output signal (i.e., resistance changes of the WB) depends strongly on bending mechanism of the membrane part of the spring. Hence, sensor sensitivity needs to be taken into consideration, which was numerically analyzed by FEM based on the resistance changes ( R/R) of the WB (Wasisto et al, 2015b):…”

Compositional Analysis of Adsorbed Organic Aerosol on a Microresonator Mass Sensor

“…The requirement of particle deposition limits the lifetime of the device (Mehdizadeh et al 2017), but in turn enables the potential for additional analysis on the collected aerosol similar to filter or conventional impactor samples. After the additional analysis is complete, microresonators can be regenerated using a number of cleaning methods presented in the literature (Mehdizadeh et al 2017;Wasisto et al 2013Wasisto et al , 2013Wasisto et al , 2015Zielinski et al 2017) and reused for further measurements.…”