Interfacing Biomolecules, Cells and Tissues with Nanowire-based Electrical Devices - Applications of Electrochemistry and Nanotechnology in Biology and Medicine - page 88

parent substrate allowing simultaneous optical imaging and elec-
tronic recording in configurations that are not readily accessible
with traditional planar device chips, yet advantageous for produc-
ing diverse, functional tissue-device interfaces. It allows for both
visual inspection, which enables rough orientation of the device
array to the heart, and higher-resolution imaging through the
transparent substrate while recording from NWFET devices. Nota-
bly, recording from a representative NWFET device in this invert-
ed configuration demonstrated excellent S/N fast component peaks
correlated with the spontaneously-beating heart. Still, the average
magnitude of the conductance peaks and calibrated voltage are
similar to that recorded in more traditional planar configuration. In
addition, similar recording were achieved on beating hearts in
which bent chips were oriented with convex NWFET surface
wrapped partially around the heart.
These results demonstrate that these flexible and transparent
NW chips can be used to record electronic signals from organs in
configurations not achievable by conventional electronics. We
believe that NWFET arrays fabricated on flexible plastic and/or
biopolymer substrates can become unique tools for electrical re-
cording from other tissue/organ samples or as powerful implants.
VI. NANOWIRES-BASED TRANSISTOR FLEXIBLE
ARRAYS FOR THE ELECTRICAL
RECORDING OF CARDIOMYOCYTES
One of the difficulties of culturing live cells over electrical devices
is maintaining good device characteristics. Devices can suffer from
destructive effects such as corrosion, solution drift, electrical
shorts, etc. To address these key issues, a flexible approach was
developed to interface NW FET arrays with cultures of cardiomy-
ocyte monolayers cultured on optically-transparent PDMS sheets
that were brought into contact with the devices. 44 It allowed to
grow the cells separately, identify desired specific cell regions and
place them over the NWFET devices, and more importantly, to
investigate the relationship between the interface and signal mag-
nitude which is critical to understand in relation to cells and na-
noscale structures. Rat cardiomyocytes were shown to grow on