A micro ion drag pump with planar electrodes on a glass substrate is fabricated and tested. The pump consisted of a 2-dimensional electrode pair array is driven by DC voltage using unipolar conduction. Ethyl alcohol is pumped in both directions, and the flow rate and the pressure are measured, in channels of depth 100μm or 200μm and width fixed at 3mm. It is found that the pump could be fabricated easily and at lower cost than the micro ion drag pumps previously investigated.
Output responses of an tin-oxide gas sensor depends on indoor temperature/humidity, but not on the reacted gas concentrations. The modeling of a gas sensor characteristics curve between gas concentrations and voltage was attempted with respect to a temperature/humidity change, to remove the influence of indoor environment from sensor responses. A characteristics curve was derived as an inverse proportion function and approximated by undecided variables with a plane approximation of temperature/humidity coefficients. The results of this study in a home indicate that each temperature/humidity coefficient is approximate to linear equation in error ranges of 5% and approximate functions of a characteristics curve are in a mean error range of about 1% for a reserved region.
Response mechanism of a membrane made of trioctylmethylammonium chloride (TOMA) to ethanol was studied. The response of the TOMA membrane to ethanol increased linearly with increasing ethanol concentration (0-20%) at constant KCl concentration. The slope of response to ethanol was-1.73 (mV/ethanol%) using the multiple regression analysis (0-20% ethanol, 1-100 mMKCI). The value of this slope calculated using the transfer activity coefficient of chloride ion from water to ethanol showed a good agreement with the experimental value. On the other hand, the results obtained in AgCl and anion exchange membrane disagreed with the theoretical values.
Etching on Si{110} in KOH aqueous solutions containing a small amount of Cu has been studied. It is found that 100ppb-level Cu in KOH aqueous solution forms pyramidal shaped hillocks of Si and roughes the etched surface. It is understood that the hillocks are caused by masking effect of Cu particles deposited on Si. The results also show that 100ppb-level Cu reduces the etching rate since the hillocks consist of slowly etched {311} planes