Flexible & stretchable electronics for biointegrated devices.. NIT BHOPAL
FLEXIBLE & STRETCHABLE
ELECTRONICS FOR BIOINTEGRATED
Presented by :
Nitin Kumar choukiker
• Bio-integrated electronic devices act like an
interface between doctors and suffering patients.
• Develop high performance flexible and
electronic and optoelectronic devices using high
quality single crystal inorganic materials.
• Apply these technologies for the health monitor
and therapy systems.
Bendability & stretchability of
inorganic electronic materials
• Inorganic materials such as silicon and metals are stiff
and readily break when their intrinsic strain exceeds
even very small values, such as 1 percent.
• Basic beam theory predicts that the bending-induced
maximum strain of a membrane is proportional to the
product of film thickness and bending curvature.
• If the maximum strain is limited to a critical strain to
rupture of the material (1%), the maximum allowable
bending curvature will be inversely proportional to the
thickness of the membrane.
Extreme bendability and flodability in
Bio-integrated devices in
• Electroencephalograph (EEG) measurements, based on
epidermal electronic systems laminated on a human forehead
in a manner much like a temporary transfer tattoo,
mechanically invisible to the wearer.
• Attachment is enabled by van der Waals force without any
conductive gels, these systems can function for more than two
weeks at the exact same position without decomposition of
• Depending on where the electronic tattoo is placed, EEG, ECG
measurements are possible with very high signal-to-noise
• In addition to electrophysiological sensing, studies have
successfully demonstrated the monitoring of skin
temperature, mechanical deformation (strain), mapping of
• When large ensembles of neurons fire synchronously, a large
electricfield is generated and can be measured on the scalp,
• Alpha range neural activity(8-12hz) reflect the attention to
• When subject gain visual attention focus, amplitude of alpha
oscillation decreases(eye open), while amplitude of alpha
oscillation increases by losing visual attention focus(eye
Bio-integrated devices in brain:
• Flexible brain-computer interfaces (fBCIs)
are microelectrode array fabricated on layers
of polymers (e.g.polyimide).
• to record and process neuronal signaling pattern
• to use this data to control an external device. The
increased bendability of these devices make them
less harmful to brain tissues after
immediate implantation .