Dynamic Polymeric Microtubes for the Remote-Controlled Capture, Guidance, and Release of Sperm Cells

Remote-controlled release of single sperm cells is demonstrated by the use of polymeric microtubes that unfold upon temperature increase to 38 degrees C. Thermo-responsive, ferromagnetic multilayers are tailored to catch sperm cells and remotely control them by external magnetic fields. These polymeric spermbots are propelled by the sperm flagella. When the temperature is increased, the tubes unfold and the cell is set free.