Needle seal force sensor

A method for force sensing comprising:

• configuring a computing device to have a desired force setting;
• determining, using said computing device in accordance with a desired force setting, a first vertical position of a needle;
• sending a control signal from said computing device to a positioning device;
• positioning, in response to said control signal and using said positioning device, said needle at said first vertical position, wherein when in said first vertical position, surfaces of an end face of one end of said needle are in contact with surfaces of sidewalls in an opening of a sealing member and said positioning causes application of a force, to said end face of said one end of the needle, downward in a vertical direction to form a substantially fluid tight seal between surfaces of said sidewalls of the opening in contact with surfaces of said end face of the one end of said needle, wherein said end face of said one end of said needle faces said vertical direction in which the force is applied;
• compressing, responsive to application of said force, a spring a distance vertically that is proportional to said force applied in the vertical direction;
• and
• measuring said force using a force sensor, wherein when positioning the needle, once the surfaces of the end face of the needle are in contact with the surfaces of the sidewalls in the opening of the sealing member, further downward vertical movement to position the needle results in the sealing member being pushed vertically downward thereby causing compression of the spring towards the force sensor.