I am trying to identify a motor-driven system that can produce a constant linear force in one direction.
The context for this is an injection device that compresses the plunger of a syringe (similar setup to this open source syringe pump). The actuation (injection) needs to be performed at a precise and repeatable force. I'm not trying to control for the speed of the linear motion, only the force driving it. The linear force then determines the speed (flow rate) of the injection based on the fluid dynamics of the drug solution. For example, at a constant linear force, a higher viscosity drug will be injected at a slower rate than a lower viscosity drug.
I would like to be able to generate different linear forces from a single motor in order to achieve different injection speeds. I know a stepper motor can not achieve this as it only operates at maximum torque. Can a servo motor achieve this?
Also, is it possible to accurately set the force output (e.g. program one = 4 N ; program two = 10 N)?