Resistance Changing Sensor

A method of constructing a sensor for detecting an external interaction by effecting a change in resistance, comprising the steps of:

• defining a first layer of a conductive material;
• defining a first layer of a conductive material;
• attaching a first electrode to said first layer of a conductive material;
• defining a second intermediate layer of a material having a resistance sensitive to external interactions;
• defining a third layer consisting of a first set of fingers interdigitated with a second set of fingers;
• attaching a second electrode to said first set of fingers and attaching a third electrode to said second set of fingers;
• connecting said first electrode to said second electrode to make a parallel connection;
• applying a voltage between said parallel connection and the third electrode;
• and
• measuring an electrical signal to obtain a measurement which is dependent upon current flowing from said parallel connection to the third electrode.