  Flexible electronic devices require the integration of multiple crucial
components on soft substrates to achieve their functions. In particular, memory
devices are the fundamental component for data storage and processing in
flexible electronics. Here, we present flexible MgO barrier magnetic tunnel
junction (MTJ) devices fabricated using a transfer printing process, which
exhibit reliable and stable operation under substantial deformation of the
device substrates. In addition, the flexible MTJ devices yield significantly
enhanced tunneling magnetoresistance (TMR) of ~300 % and improved abruptness of
switching, as residual strain in the MTJ structure induced by the fabrication
process is released during the transfer process. This approach could be useful
for a wide range of flexible electronic systems that require high performance
memory components.
