RESUMEN
This paper presents newly developed two high-precision CMOS proximity capacitance image sensors: Chip A with 12 µm pitch pixels with a large detection area of 1.68 cm2; Chip B with 2.8 µm pitch 1.8 M pixels for a higher resolution. Both fabricated chips achieved a capacitance detection precision of less than 100 zF (10-19 F) at an input voltage of 20 V and less than 10 zF (10-20 F) at 300 V due to the noise cancelling technique. Furthermore, by using multiple input pulse amplitudes, a capacitance detection dynamic range of up to 123 dB was achieved. The spatial resolution improvement was confirmed by the experimentally obtained modulation transfer function for Chip B with various line and space pattens. The examples of capacitance imaging using the fabricated chips were also demonstrated.
RESUMEN
An attempt was made to detach bacterial biofilm, formed by Staphylococcus epidermidis, by using hydrogen peroxide (H(2)O(2)) and tungsten compounds. When iron(II) (Fe(2+)) was mixed with undecatungstophosphate ([PW(11)O(39)](7-)) and then H(2)O(2), the resulting mixture was able to totally remove the biofilm probably because of co-generation of (1)O(2) and .OH. A mixture of undecatungstosilicate ([SiW(11)O(39)](8-)) and Fe(2+) (or Cu(2+)) also gave a good result, but their catalytic activities for producing .OH (or (1)O(2)) were rather weak. An electron microscopic study showed that almost nothing was visible on the surface of a biofilm-coated glass after treatment with 1mM [PW(11)O(39)](7-)+1 mM Fe(2+) and 500 mM H(2)O(2) (incubated for 1 h at 37 degrees C).