USER INTRRACTIVE ELECTRONIC
SKIN(E-SKIN) FOR INSTANTNEOUS
What is ELECTRONIC SKIN?
Material which mimics the Human Skin in one or
Human skin can sense pressure , temperature ,
stretch and can heal itself
Where it is used?
DEVELOPMENT OF E-SKIN
I. Attaching nanowire transistors to sticky substrate,
embedded in in thin pressure sensitive rubber-capable of
sensing wide range of pressures(California University)
II. First prototype for e-skin
I. Stretchable solar cell used to power the electronic
I. Self healing capacity
II. Made by plastic and nickel
DEVELOPMENT OF E-SKIN(cont..)
I. No requirement of high temperature for self healing
• Optimization of pressure sensors & Electronic read out-but no
Human Readable output.
• The new e-skin: Spatially map the applied pressure and
instantaneous visual response through OLED.
• BUILT IN ACTIVE ORGANIC LED DISPLAY: OLEDs are turned on
locally where the surface is touched and the intensity of the
emitted light quantifies the magnitude of the applied
• System on plastic Demonstration 1.Thin film Transistor
How Visual response is achieved?
• Grid of vertical and
• Each pixel is controlled by
an intersection of 2 wires
• Color and brightness is
altered by changing
• Each pixel is controlled by TFT
thin film transistors
• Act as switch for addressing
either voltage or current
• TFTs contains Semiconductor
enriched nanotubes as the
• Carbon nanotubes-High
current drives for OLEDs
Structure of pixel of e-skin
• Nanotube TFT drain
connected to anode of
• OLED: Bi-layer structure
whose color controlled by
emissive layer material.
• PSR: Electrical contact with
cathode of OLED.
• Conductivity of PSR α
Electrical performance of carbon nano
L=20 um, W=2000 Vds=-5v
Offset current of the transistor varies from 0.1 to 3uA.For this
work this variation is acceptable. But can be again reduced by high
• Led whose electroluminescent layer is organic compound.
• OLED Vs LCD
• Low power consumption, Faster refresh rate
• Better contrast
• Greater contrast, Brightness.
• Better durability-Better temperature range.
• By simply changing emissive layer the emitted peak
wavelength can be adjusted to 489,523,562,601 nm.
How to control OLED
• Control ckt: By interconnecting the anode of an OLED with
carbon nanotube TFT.
•By sweeping the gate voltage/Power supply Vdd of the
control TFT, the current flowing through OLED can be
controlled which translates in to the modulation of OLED
brightness allowing the OLEDs to be turned ON and OFF.
• We can arrange above described single pixel OLED control
circuitry in to an active matrix OLED which then integrated
with pressure sensor to get e skin.
•Above figure represents Single color flexible AMOLED display
with -5 and 10 v applied to all of the scan and data lines
The above figure shows full color display being fully
turned on in the relaxed and bent states.
Each pixel can be individually addressed using nanotube
How to convert display in to e-skin
• PSR lamination on the top of the leads to make
• The cathode of each OLED is connected to the
ground through PSR. Application of pressure:
shortening of tunneling path between conductive
carbon nano particles-reduced resistance of PSR
modulates the current flowing through the OLEDs
and changes the brightness of the output.
• First demonstration of a user interactive flexible
system that can not only detect the spatially map
external stimuli but also respond with an integrated
• System enables sensed pressure profile to be
instantaneously visible without the need for
sophisticated data acquisition ckts and electronic
• Automatic control panel
• Interactive input devices
• Medical & Health monitoring device