An infusion set, patch pump, or elements thereof, having an exemplary catheter (14) provided with one or more channels, grooves and coatings (24, 34, 44), configured and arranged to provide a degree of strength and flexibility. The catheter (14) can also have an exemplary flexible union with the hub (12) having at least one of a ball-and-socket joint (66, 68), a sliding plate (86), and a flexible bushing (106), and which is sealed to allow even further movement of the catheter (14) while preventing leakage of medication through the junction. In doing so, a number of benefits associated with the use of rigid materials in catheter construction can be provided while at the same time, benefits associated with the use of flexible materials in catheter construction and/or flexible engagement with the hub can also be provided.
