Step 3: Moisture sensing matrix
For the inside of the pillow I wanted to create a matrix under the surface that would allow the circuit to be completed when moisture was present, but be unobstructive at all other times. For this, I cut my fine wire mesh fabric into long strips and sewed them into spaced rows. Make sure to cut your mesh fabric on the bias so that the edges don't fray. Alternating rows were connected together using the same mesh fabric. Your moisture matrix can be as large as you like, and even on both sides of your pillow. For this design I chose half the pillow's area on one side only.
Keep your multimeter on hand and test for conductivity. You do not want any frayed edges to complete the circuit without moisture. When your matrix is sewn in successfully another layer of fusible bonding matrix was added on top to keep the mesh fabric in place and prevent any false connectivity once the wiring is complete. Another scrap piece of cotton fabric was iron onto the fusible bonding matrix after. A small gap was left to allow the circuit wires to be hooked up to the moisture sensing matrix. Conductive fabric leads were covered in heat-shrink tubing and sewn from each side of the matrix. These leads will be joined with the moisture sensing probes on the circuit.