Memory weave
From Tardis Wiki, the free Doctor Who reference
The memory weave was a device capable of extracting memories and turning them into physical objects. The Claw Shansheeth tried to use a memory weave to create a TARDIS key from the memories of Sarah Jane Smith and Jo Jones. The machine overloaded when the women remembered all of their time with the Doctor and other significant adventures from their lives. It exploded, killing Tia Karim and the Shansheeth. Sarah Jane and Jo survived by taking shelter in a lead-lined coffin. (TV: Death of the Doctor)