Self-expandable medical devices provide mechan-
ical functionality at a specific location of the human body and
are viable for minimal invasive procedures. Besides radi-
opaque markers and drug-eluting coatings, next generation
self-expandable devices can be equipped with additional func-
tionality, such as conductive and flexible electrodes, which
enables chronic recording of bioelectrical signals, stimulating
or ablating tissue. This promises new therapeutic options in
various medical fields, among them in particular
neuromodulation (e.g. deep brain stimulation), BioMEMS,
radio frequency ablation, mapping or denervation. However,
the fabrication of such multi-functional devices is challenging.
For this study we have realized a 35 μm thick, superelastic
NiTi thin film stent structure with six isolated electrodes on
the outer circumference, each electrode connected to a contact
pad at the end of the stent structure, using magnetron
sputtering, UV lithography and wet chemical etching.
Mechanical and electrical properties of the device during typ-
ical loading conditions, i.e. crimping, simulated pulsatile and
electrochemical testing, were characterized and reveal prom-
ising results. For the fabrication of future multifunctional,
minimal invasive medical devices, such as electroceuticals
or other intelligent implants, NiTi thin film technology is
therefore a versatile alternative to conventional fabrication
routes.

• Fabrication of self-expandable NiTi thin film devices with micro-electrode array for bioelectric sensing, stimulation and ablation