The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper reports a MEMS-based particle size spectrometer using a micromachined cascade impactor. While a MEMS-based particle counter presented in our previous research was developed for measuring the total number concentration of particles within certain size range, the proposed particle size spectrometer is developed for measuring airborne particle size distribution. To the best of our knowledge,...
This paper reports a novel micromachined corona-based unipolar aerosol charger for improving particle charging efficiency. The particle charging efficiency is an important parameter in aerosol measurement. The low charging efficiency of the previous tip-to-plate corona charger due to charged particle losses led to difficulty in aerosol measurement. The proposed corona charger could reduce the electrical...
This paper reports on the full realization of an ultrafine particle monitoring system, including a MEMS-based particle processing chip and signal processing circuits. Unlike a conventional liquid-based microfluidic chip, the proposed particle processing chip handles a mixture of gas and particles. The proposed particle monitoring system is suitable for routine ambient air monitoring due to its small...
This paper reports a micromachined corona discharger with slit dielectric barrier for measuring the number concentration of airborne particle. The tip-to-plate corona discharger presented in our previous research only generates the corona discharge on the tip type electrode. However, the proposed corona discharger generates the corona discharge on the slit dielectric barrier as well as the tip type...
This paper reports an electrodynamic anti-adhesion technique to detach particles adhered to the wall of microchannels. Electrodynamic disturbance is generated by applying electric potential at the frequency of 100 Hz to the interdigitated electrodes integrated at the bottom of the microchannel. Polystyrene latexes, ranging in diameter from 0.5 to 1.1 mum, were supplied to the microchannel. Before...
This paper demonstrates a hybrid particle classification and condensation device based on both aerodynamics and electrostatics using a micro virtual impactor (muVI). The muVI is capable of classifying the nanoparticles according to their size and condense their number concentration that we are interested. The muVI was fabricated using polymer micromachining. Its classification efficiency was examined...
This paper demonstrates a hybrid jetting system (HJS) using both electrohydrodynamic (EHD) force and mechanical actuation to generate ultra fine droplets with drop on demand (DOD). In the proposed HJS, liquid meniscus was formed by a piezoelectric actuator and jets were generated by EHD force. Jetting characteristics were also examined for hydrophobicity and hydrophilicity of a surface of a capillary...
Electrohydrodynamic jet printing (EHDP) technique is widely used for the direct writing. However, in the existing EHDP method, the printing characteristics are affected by the printing substrate used, and the printed line width is determined by the geometry of the nozzle. We propose an EHDP method which is capable of (1) removing the effect from the substrate, and (2) controlling the line width through...
This paper reports a micromachined nano electrical mobility analyzer (nEMA) for nano- sized airborne particle classification. The micromachined nEMA is a particle classifier that uses both the inertia and electrical mobility of the particles for the classification. The microchannel of the nEMA is defined by silicon bulk micromachining. The collection efficiency of the solid particle, NaCl with a diameter...
We report design, fabrication and experimental results of a micromachined cascade virtual impactor with flow rate distributor for classifying airborne particles according to their sizes. The fabricated device consists of two components: a cascade virtual impactor for classifying particles according to their own inertia, and a flow rate distributor to maintain specific flow rates at each channel. Proposed...
Increased disk rotational speed of hard disk drive and contamination by nanoparticles can cause serious problems including thermal asperity (TA). In this study, the filtration efficiency of recirculation filter system in the hard disk drive was investigated with various particle contamination locations and disk rotational speeds. In result, the filtration efficiency was clearly affected by the particle-generated...
High performance disk drives require high spindle speed. The spindle speed of typical hard disk drives has increased in recent years. The increasing disk velocity leads to increasing disk acceleration and slider-disk interaction. The slider-disk interaction in CSS (contact-start-stop) mode is an important source of particle generation and tribocharge. Charge build-up in the slider-disk interface can...
As the flying height of a slider in a hard disk drive decreases, the head and disk are more likely to come in contact and to generate contamination particles. Since particle contamination can cause serious problems including thermal asperity, its removal is very important to increase storage capacity. When particles are generated in a HDD, particles could be charged by several charging mechanism and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.