Methods for manufacturing a microstructured sensor

A method for making a sensor for measuring conductivity or capacitance of gases or liquids, comprising:

• sputtering an adhesion layer and an initiator layer onto a substrate;
• applying and structuring a resist layer onto the initiator layer to form a pattern of the metallic three-dimensional interdigital electrode arrangement, the metallic three-dimensional interdigital electrode arrangement including a plurality of electrodes;
• electroplating grooves in the resist layer to form a metallic three-dimensional interdigital electrode arrangement;
• and
• after the electroplating, removing the resist layer, and removing the initiator layer between the electrodes of the metallic three-dimensional interdigital electrode arrangement.

A method for manufacturing a sensor, the sensor including a three-dimensional interdigital electrode arrangement positioned on a substrate, the method comprising the steps of:

• applying at least one of a temperature sensing resistor and a heating resistor onto the substrate by sputtering a first adhesion layer and a first metallic layer onto the substrate, applying and structuring a first resist material on the first metallic layer, and etching the first metallic layer in resist free areas;
• and
• applying a three-dimensional interdigital electrode arrangement onto the substrate, the three-dimensional interdigital electrode arrangement including a plurality of electrodes, each of the electrodes having vertical surfaces and a horizontal surface, the vertical surfaces extending vertically from a surface of the substrate, the horizontal surface being horizontal relative to the surface of the substrate, the three-dimensional interdigital electrode being applied onto the substrate by:
• i) sputtering a second adhesion layer and an initiator layer onto the substrate, ii) applying and structuring a second resist material on the initiator layer to form a pattern of the three-dimensional interdigital electrode arrangement having fingers, after the structuring, iii) filling resist valleys by electroplating;
• and iv) after the filling, removing the second resist material, and removing the initiator layer between the fingers of the three-dimensional electrode arrangement;
• wherein the three-dimensional interdigital electrode is applied so that for each of the electrodes, a surface area of the vertical surfaces is larger than a surface area of the horizontal surface.

A method for making a sensor for measuring conductivity or capacitance of gases or liquids, comprising:

• sputtering an adhesion layer and an initiator layer onto a substrate;
• applying and structuring a resist layer onto the initiator layer to form a pattern of the metallic three-dimensional interdigital electrode arrangement having a plurality of electrodes, each of the electrodes having vertical surfaces and a horizontal surface, the vertical surfaces extending vertically from a surface of the substrate, and the horizontal surface being horizontal relative to the surface of the substrate;
• electroplating grooves in the resist layer to form a metallic three-dimensional interdigital electrode arrangement so that for each of the electrodes, a surface area of the vertical surfaces is larger than a surface area of the horizontal surface;
• and
• after the electroplating, removing the resist layer, and removing the initiator layer between the fingers of the metallic three-dimensional interdigital electrode arrangement.

A method for making a sensor for measuring conductivity or capacitance of gases or liquids, comprising:

• sputtering an adhesion layer and an initiator layer onto the substrate;
• applying and structuring a resist layer onto the initiator layer to form a pattern of a metallic three-dimensional interdigital electrode arrangement having a plurality of electrodes, each of the electrodes having vertical surfaces and a horizontal surface, the vertical surfaces extending vertically from a surface of the substrate, and the horizontal surface being horizontal to and spaced from the surface of the substrate;
• electroplating grooves in the resist layer to form a metallic three-dimensional interdigital electrode arrangement so that for each of the electrodes, a height of the vertical surface is larger than a width of the horizontal surface;
• and
• after the electroplating, removing the resist layer, and removing the initiator layer between the fingers of the metallic three-dimensional interdigital electrode arrangement.