belt drives and encoders in order to convert rotational motion into linear motion and control the motor's motion. Both the stepper and DC motors come Commutation system in a small, lightweight package that allows designers to optimize the weight of their devices. However, these motor technologies come with trade-offs. For example, some DC motors are less expensive than linear stepper motors, but the additional components needed for the transmission must be considered. Pipette designers must also consider the potential errors and tolerances associated withhttp://info.hotims.com/82327-754 http://www.medicaldesignbriefs.com