Solid phase sensors

A method of forming a solid phase array of electrical sensors comprising:

• forming pillars on a surface of a substrate;
• conducting a surface-initiated oxidative conversion reaction to convert the lateral exterior of the pillars to a form more resistive to an isotropic etching process, while not converting cores of the pillars;
• conducting an etching process to form channels from the cores;
• forming larger cavities in the substrate beneath and connected to the channels, and forming electrical leads on the substrate connected to both sides of each of the channels, such that, when attached to an appropriate metering device, voltages, currents or resistivities through the channels can be measured.