A mechanism for opening and closing a resealable cartridge includes a base for receiving a cartridge, a roller shaft for engaging a cover adhesively disposed on the cartridge, a motor for rotating the roller shaft, and a slidable carriage that supports the roller shaft and the motor. The motor rotates the roller shaft in a first direction to peel the cover away from the cartridge, and in a second direction to reseal the cover to the cartridge. The motor includes a rotor shaft, coupled in substantial alignment with the roller shaft, for applying rotational torque to the roller shaft without applying undesirable radial forces that can damage the cartridge cover, thereby extending cartridge life. The coupling of the rotor shaft also eliminates the need for a complicated gear train, resulting in reduced size, ease of repair, and enhanced reliability. The roller shaft includes a compliant friction coating that evenly distributes sealing force over the cover during closure. The compliant friction coating also produces added driving traction that helps the roller shaft drive the carriage during both the opening and closing operations, thereby avoiding stretching of the cover. The carriage is slidably coupled to the base, resulting in further size reductions. The mechanism is essentially modular in design, facilitating repairs and enabling replacement of the mechanism with a spare to reduce down time.