High sensibility pressure sensor

Abstract

A pressure sensor includes a first layer of electrically insulating material, a second layer of electrically insulating material superposed on the first layer, and at least one electrical switch. The electrical switch includes: at least one electrical contact associated with the first layer, and an electrical conductor associated with a flexible portion of the second layer, which is separate from the first layer and is directly superposed on said electrical contacts.

1 . A pillow comprising a soft mat and a pressure sensor, wherein the pressure sensor comprises:
 a first layer of electrically insulating material, the first layer being in the form of a sheet,   a second layer of electrically insulating material superposed on the first layer, and   at least one electrical switch,   
       wherein said at least one electrical switch comprises:
 at least one electrical contact associated with the first layer, and 
 at least one electrical conductor associated with a flexible portion of the second layer, which is separate from the first layer and is directly superposed to said at least one electrical contact, 
 
       said at least one electrical switch comprises a support layer having greater rigidity than the flexible portion of the second layer, which is applied on the first layer at an opposite side from said flexible portion and aligned therewith. 
     
     
         2 . The pillow according to  claim 1 , wherein the first layer is a flexible sheet of insulating material. 
     
     
         3 . The pillow according to  claim 2 , wherein the first layer has a thickness between 0.1 mm and 0.3 mm. 
     
     
         4 . The pillow according to  claim 2 , wherein the second layer is in the form of a flexible sheet of insulating material. 
     
     
         5 . The pillow according to  claim 4 , wherein a thickness of the second layer is greater than a thickness of the first layer. 
     
     
         6 . The pillow according to  claim 4 , wherein the first layer has a thickness of 0.1 mm and the second layer has a thickness of 0.18 mm. 
     
     
         7 . The pillow according to  claim 6 , wherein a distance between the flexible portion and the plane of lay of the second layer is between 0.8 mm and 1.2 mm. 
     
     
         8 . The pillow according to  claim 1 , wherein the at least one electrical conductor associated with a flexible portion of the second layer and the at least one electrical contact associated with the first layer are obtained by a printing process with a silver-based paste or a carbon-based paste. 
     
     
         9 . The pillow according to  claim 1 , wherein at least one pair of electrical contacts electrically insulated from one another is associated with the first layer, and wherein the flexible portion of the second layer is directly superposed on said at least one pair of electrical contacts. 
     
     
         10 . The pillow according to  claim 1 , wherein the at least one electrical contact and the at least one electrical conductor are in the form of conductive strips applied respectively on the first and on the second layer. 
     
     
         11 . The pillow according to  claim 1 , wherein the flexible portion of the second layer presents a concave conformation with its concavity oriented towards the first layer. 
     
     
         12 . The pillow according to  claim 1 , further comprising a third layer of electrically insulating material interposed between the first and the second layer, said third layer being provided with at least one through opening aligned with the flexible portion of the second layer. 
     
     
         13 . The pillow according to  claim 1 , wherein said at least one electrical switch is a plurality of electrical switches. 
     
     
         14 . The pillow according to  claim 13 , wherein the electrical contacts of all the electrical switches are electrically connected to a first electrical terminal through a first electrical line associated with the first layer, and wherein the electrical conductor of all the electrical switches are electrically connected to a second electrical terminal, separate from the first terminal, through a second electrical line associated with the second layer. 
     
     
         15 . The pillow according to  claim 1 , further comprising an electronic unit electrically connected to the electrical contact associated with the first layer and to the at least one electrical conductor associated with the flexible portion of the second layer, the electronic control unit being configured to verify whether said at least one electrical switch is closed. 
     
     
         16 . The pillow according to  claim 15 , wherein the electronic unit is provided with wireless communication means configured to connect the electronic unit with a separate electronic device, wherein the electronic control unit is configured to detect if a distance from the electronic device exceeds a threshold value and to transmit an alarm message to the electronic device if the distance from the external device exceeds the threshold value and if the electronic control unit detects closing of the at least one electrical switch. 
     
     
         17 . The pillow according to  claim 16 , wherein the sensor further comprises an accelerometer connected with the electronic unit. 
     
     
         18 . The pillow according to  claim 1 , further comprising a lining configured to coat the mat. 
     
     
         19 . A pillow comprising a soft mat and a pressure sensor, wherein the pressure sensor comprises:
 a first sheet of electrically insulating material,   a second sheet of electrically insulating material superposed on the first sheet,   a plurality of electrical switches, and   an electronic control unit connected to said electrical switches and configured to detect closing of at least one of the electrical switches,   
       wherein each electrical switch of said plurality comprises:
 at least one electrical contact associated with the first sheet, and 
 at least one electrical conductor associated with a flexible portion of the second sheet, which is separate from the first sheet and is directly superposed to said at least one electrical contact, and 
 a support layer having greater rigidity than the flexible portion of the second sheet, which is applied on the first sheet at an opposite side from said flexible portion and aligned therewith, wherein the electrical contacts of all the electrical switches are electrically connected to a first electrical terminal through a first electrical line associated with the first layer, and wherein the electrical conductor of all the electrical switches are electrically connected to a second electrical terminal, separate from the first terminal, through a second electrical line associated with the second layer, 
 
       and wherein the electronic control unit is configured to apply a voltage to the first electrical terminal or to the second electrical terminal and to detect the voltage on the other electrical terminal. 
     
     
         20 . The pillow of  claim 19 , wherein the electronic unit is provided with wireless communication means configured to connect the electronic unit with a separate electronic device, wherein the electronic control unit is configured to detect if a distance from the electronic device exceeds a threshold value and to transmit an alarm message to the electronic device if the distance from the external device exceeds the threshold value and if the electronic control unit detects closing of at least one of the electrical switches.