Reciprocating piston pump and method of manufacture

A reciprocating piston pump comprising:

• a pump chamber;
• a piston seal;
• a piston comprising a fluid engaging end, a seating end, and a longitudinal outer piston surface between the fluid engaging end and the seating end;
• and
• a drive assembly coupled to the seating end of the piston;
• wherein
• the drive assembly operates to reciprocate the piston within the pump chamber between full aspirate and full dispense positions,
• the piston seal forms an interface between the longitudinal outer piston surface of the piston and the pump chamber,
• the piston and the drive assembly are configured such that the piston seal interfaces with the longitudinal outer piston surface over a full stroke length of the drive assembly between full aspirate and full dispense positions, and
• the longitudinal outer piston surface comprises a partially fluorinated polymer coating.

A reciprocating piston pump comprising:

• a pump chamber;
• a piston seal;
• a piston comprising a fluid engaging end, a seating end, and a longitudinal outer piston surface between the fluid engaging end and the seating end;
• and
• a drive assembly coupled to the seating end of the piston;
• wherein
• the drive assembly operates to reciprocate the piston within the pump chamber between full aspirate and full dispense positions,
• the piston seal forms an interface between the longitudinal outer piston surface of the piston and the pump chamber, and
• the longitudinal outer piston surface exhibits a treated surface energy and a treated contact angle along at least a portion of the longitudinal outer piston surface, and a native surface energy and a native contact angle in untreated portions of the piston,
• the piston and the drive assembly are configured such that the piston seal interfaces with the longitudinal outer piston surface over a full stroke length of the drive assembly between the full aspirate and full dispense positions,
• the treated surface energy of the piston is greater than the native surface energy of the piston, and
• the treated contact angle of the piston is at least about 90 degrees, and is greater than the native contact angle of the piston.

A method of manufacturing a reciprocating piston pump comprising:

• a pump chamber;
• a piston seal;
• a piston comprising a fluid engaging end, a seating end, and a longitudinal outer piston surface therebetween;
• and
• a drive assembly coupled to the seating end;
• wherein
• the drive assembly operates to reciprocate the piston within the pump chamber between full aspirate and full dispense positions,
• the piston seal forms an interface between the longitudinal outer piston surface of the piston and the pump chamber,
• the piston and the drive assembly are configured such that the piston seal interfaces with the longitudinal outer piston surface over a full stroke length of the drive assembly between the full aspirate and full dispense positions, and
• the piston is treated with a method that comprises a piston treatment process selected such that
• the piston exhibits a treated surface energy and a treated contact angle along at least a portion of the longitudinal outer piston surface, and a native surface energy and a native contact angle in untreated portions of the piston,
• the treated surface energy of the piston is greater than the native surface energy of the piston, and
• the treated contact angle of the piston is at least about 90 degrees.