catheter as embolic coil 10 exits the delivery catheter it assumes its secondary shape which allows embolic coil 10 to fill aneurysmal sac or other structure typically the primary shape of embolic coil 10 is selected for deliverability and the secondary shape of embolic coil 10 is selected for application e g embolization of an aneurysm one exemplary secondary shape in accordance with an embodiment of the present disclosure is illustrated in fig3 a c which show various views of an embolic coil 10 with free energy secondary shapes in which a main portion 10 m defines a volume specifically a cylindrical volume and in which a proximal end 10 p is disposed within the volume additional secondary shapes in accordance with embodiments of the present disclosure are illustrated in fig7 a and 7b which show additional cutaway views of embolic coils 10 with free energy secondary shapes in which a main portion 10 m defines a volume specifically a cylindrical volume and in which a proximal end 10 p is disposed within the volume fig4 a 4d illustrate that other embolic coils may be formed which can have any number of different secondary shapes in these figures embolic coils 10 have been formed with free energy secondary shapes in which a main portion 10 m defines a volume specifically a cylindrical volume fig4 b a conic volume fig4 a and 4d and a dual conic volume fig4 c in each case the free energy secondary configuration is.