Sensor Electrode Surface Energy Layout for Uniform Reagent Layers

The electrode surface is divided into regions with different surface free energies: a first region with lower surface free energy where the reagent layer should be formed, and a second region with higher surface free energy that prevents reagent layer formation. This local differentiation of surface properties enables precise spatial control of the reagent layer, ensuring uniform dimensions and contact surface area even when the electrode is disposed in a recess.

The invention changes the surface free energy parameter of different electrode regions to control reagent layer formation. By adjusting surface free energy values (lower in the first region, higher in the second region), the patent achieves precise control over where the reagent layer forms and its dimensional uniformity, resolving the manufacturing precision issue while maintaining detection accuracy.

By creating local quality differences in surface free energy across the electrode surface, the invention makes the reagent layer formation dependent on surface properties rather than geometric position. This allows the electrode to be placed flexibly in the recess while the reagent layer consistently forms in the designated first region with controlled dimensions, decoupling placement flexibility from dimension control.

The surface free energy distribution is established beforehand on the electrode before it is disposed in the recess. This preliminary action of patterning the surface ensures that regardless of the electrode's final position or orientation in the recess, the reagent layer will form in the correct region with the intended dimensions, as the surface properties already dictate the formation location.