Controlling the Kinetics of Contact Electrification with Patterned Surfaces

This communication describes a new approach for controlling static charging (contact electrification), and resulting electrical discharging, that occurs when two contacting materials separate. The prevention of contact electrification is an important problem; unwanted adhesion between oppositely charged materials, spark-initiated explosions, and damage to microelectronic circuitry are some of the deleterious effects of static charging. Current strategies for controlling contact electrification rely upon dissipating an accumulated charge by making contacting surfaces conductive and, therefore, can be difficult to implement with electrically insulating materials. Specifically, using our understanding of the ion-transfer mechanism of contact electrification, we patterned glass slides with negatively charging areas (clean glass) and positively charging areas (glass silanized with a cationic siloxane terminated with a quaternary ammonium group). The rate of charge separation due to a steel sphere rolling on th...