Systems, devices and methods for analyte sensor insertion

An applicator for inserting an in vivo analyte sensor, the applicator comprising:

• an analyte sensor;
• a sensor electronics carrier comprising at least one deflectable lock structure;
• and
• a sharp carrier coupled to a spring and a sharp;
• wherein the sensor electronics carrier and the sharp carrier are configured to advance from a first position within the applicator in spaced relation with a skin surface to a second position adjacent to the skin surface upon application of a first force to the applicator in a first direction, wherein the sharp and a portion of the analyte sensor are positioned under the skin surface at the second position, and
• wherein the sharp carrier is configured to retract within the applicator and withdraw the sharp from the skin surface upon application of a second force to the applicator in a second direction, wherein the second force causes the at least one deflectable lock structure to disengage from the sharp carrier and to cause the spring coupled to the sharp carrier to expand.