DRYNESS/WETNESS RESPONSIVE SENSOR HAVING FIRST AND SECOND WIRES SPACED 5 nm TO LESS THAN 20 um APART

Abstract

The present invention improves the sensitivity and the responsiveness of a dryness/wetness responsive sensor utilizing a galvanic current, allowing for downsizing of the dryness/wetness responsive sensor. Instead of the conventional structure in which an anode electrode and a cathode electrode are stacked with an intervening insulator, the present invention employs a structure in which both electrodes run in juxtaposition with each other on an insulating substrate in the form of, for example, a comb-shaped electrode as shown in the drawing. By utilizing a semiconductor manufacturing process or any other micro/nano-fabrication technology, an inter-electrode distance can be extremely shortened as compared with the conventional sensors, allowing enhancing the sensitivity per unit footprint of the electrodes. Accordingly, a decrease in the size of the dryness/wetness responsive sensor can be easily achieved.

1 - 13 . (canceled) 
     
     
         14 . A dryness/wetness responsive sensor comprising
 a thin wire of a first metal,   a thin wire of a second metal, the second metal being different from the first metal, and   a current measurement means electrically connected to the thin wire of the first metal and the thin wire of the second metal,   wherein the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other on an insulating substrate,   wherein a spacing between the first thin wire and the second thin wire is in a range of 5 nm or more and less than 20 μm.   wherein a part of the insulating substrate corresponding to the spacing between the thin wire of the first metal and the thin wire of the second metal has an insulating surface over the entire part.   
     
     
         15 . The dryness/wetness responsive sensor according to  claim 14 ,
 comprising a plurality of at least one selected from the group consisting of the thin wire of the first metal and the thin wire of the second metal, and   wherein the thin wire of the first metal extends from a first side towards a second side that is opposite to the first side and the thin wire of the second metal extends from the second side towards the first side such that the thin wire of the first metal and the thin wire of the second metal run in parallel.   
     
     
         16 . The dryness/wetness responsive sensor according to  claim 14 , wherein the thin wire of the first metal and the thin wire of the second metal are arranged in a double spiral. 
     
     
         17 . The dryness/wetness responsive sensor according to  claim 14 , wherein the insulating substrate is a silicon substrate with a silicon oxide film on its surface. 
     
     
         18 . The dryness/wetness responsive sensor according to  claim 14 , wherein the first metal is selected from a group consisting of gold, platinum, silver, titanium, an alloy thereof, and carbon. 
     
     
         19 . The dryness/wetness responsive sensor according to  claim 14 , wherein the second metal is selected from a group consisting of silver, copper, iron, zinc, nickel, cobalt, aluminum, tin, chromium, molybdenum, manganese, magnesium, and an alloy thereof. 
     
     
         20 . The dryness/wetness responsive sensor according to  claim 14 , wherein a number of pairs of the thin wire of the first metal and the thin wire of the second metal is more than 50. 
     
     
         21 . The dryness/wetness responsive sensor according to  claim 14 , further comprising a meshed member covering an area in which the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other. 
     
     
         22 . The dryness/wetness responsive sensor according to  claim 14 , further comprising an insulating protection film covering an area in which the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other, and
 wherein the insulating protection film has a groove-shaped opening that exposes at least a part of the thin wires.   
     
     
         23 . The dryness/wetness responsive sensor according to  claim 22 , wherein the groove-shape opening further exposes at least a part of a gap between the thin wire of the first metal and the thin wire of the second metal. 
     
     
         24 . The dryness/wetness responsive sensor according to  claim 14 , wherein the insulating substrate comprises an opening portion passing through from one side to an opposite side of the insulating substrate, and the opening portion is obtained by removing at least a part of the insulating substrate corresponding to the spacing between the thin wire of the first metal and the thin wire of the second metal. 
     
     
         25 . A dryness/wetness responsive sensor assembly for remote installation comprising the dryness/wetness responsive sensor according to  claim 14  attached to an attachment member having an attachment portion at one end for attachment to an object such that the dryness/wetness responsive sensor is attached to the object via the attachment member.