A surgical instrument comprises a first portion encapsulated by a membrane and a second portion comprising a surgical instrument body and a cavity in the surgical instrument body. The cavity is configured to receive the first portion. The second portion comprises a first region comprising an opening in communication with the cavity, and a closure member movable between a first position and a second position. The closure member is in sealable engagement with the second region when it is in the first position and is at least partially free from sealable engagement with the second region when it is in the second position. One or more electrical contacts on the first portion or the second portion are configured to penetrate the membrane to allow a connection to be made between the first portion and the second portion when the closure member moves from the second position into the first position.