A polysiloxane film comprises Si—O bonds and has a thickness of 0.3 to 1.5 microns. Adjacent electrodes coated with the polysiloxane film have a leakage current of at most 0.01 mA at 10 V after contact with water. An electrode coated with the polysiloxane film has a contact resistance of at least 0.01 ohms at 1.0 mm of pogo pin compression under a 1.0 N load. The polysiloxane film provides IPx7 protection from ingress of water.