World's 1st heat driven transistor

1. The world's first heat-driven transistor
Nishchay Kumar Singh
B.Tech Final Year (ECE)

2.  Introduction
 Electronics temperature Sensors
 Pyroelectric and Thermoelectric Sensors
 Construction and Working
 Properties
 Advantages and Disadvantages
 Possibilities for new applications
 References

3. Transistors

4. “We are the first in the world to present a logic
circuit, in this case a transistor, that is controlled by a
heat signal instead of an electrical signal,”
Professor Xavier Crispin
Laboratory of Organic Electronics,
Linköping University.

5.  Transistor, that is controlled by a
heat signal instead of an electrical
signal.
 The world's first heat-driven
transistor.
 A temperature rise of a single
degree is sufficient to cause a
detectable current modulation in the
transistor.
 The high sensitivity to heat, 100
times greater than traditional
thermoelectric materials.
 High seebeck cofficient 100 times to
the thermoelectric material.

6.  Thermoelectric:- it converts thermal energy or
temperature difference in detectable electrical
output signal.
 Ionic :-its operation based upon ion conducting
polymers.
 Organic :-FET which use organic semiconductor
in its channel.
 Its function is based on the use of P3HT as the
active semiconducting layer and (P(VPA-AA)) as
the polyanionic electrolyte insulator.

8.  They does not need external electrical input signal.
Thermoelectric Sensors
 They produce output voltage proportional to change in
temperature(V = SΔT).
 Low seebeck coefficient about 100 μV K−1.
 Low sensitivity , very small temperature difference produce very
weak voltage output signal .
Pyroelectric Sensors
 Which measure transient changes in incident infrared radiation.
 It is an infrared sensitive optoelectronic component .
 High sensitivity, large voltage produced per amount of incident
infrared light (104 V/W).
 They are sensitive to vibration.
 Under constant input output fluctuate.

9.  Large seebeck coefficient found in polymer electrolyte.
 The researchers at the Laboratory of Organic Electronics had searched among
conducting polymers and produced a liquid electrolyte with a 100 times greater ability
to convert a temperature gradient to electric voltage than the electrolytes previously
used.
 Researchers develops heat gated Transistor.
 The liquid electrolyte consists of ions and conducting polymer molecules. The
positively charged ions are small and move rapidly, while the negatively charged
polymer molecules are large and heavy.When one side is heated, the small ions move
rapidly towards the cold side and a voltage difference arises.
 The heat-driven transistor builds on research that led to a supercapacitor being
produced a year ago, charged by the sun's rays. In the capacitor, heat is converted to
electricity, which can then be stored in the capacitor until it is needed.
"When we had shown that the capacitor worked, we started to look for other
applications of the new electrolyte”
Xavier Crispin.

10. Ionic thermoelectric gating organic transistors (Heat Gated Transistor) is
developed by combining Electrolyte-gated transistor and Ionic
thermoelectric voltage generators.
 The PEO-NaOH solution is then injected into a small cylindrical cavity
(1.5 mm thick, diameter of 10 mm), comprising two planar gold electrodes.
 When a temperature different ΔT is applied between the two electrodes, the
more mobile Na+ cations diffuse fast towards the cold side, while
uncompensated less mobile alkoxylate and carboxylate anions remain at the
hot side.
 This generates a high voltage between the two electrodes

11. (a) Schematic diagram of the ITVG
(b) and (c)Transfer characteristics of ITVG

12. Bottom contact, top gate transistors are fabricated using regioregular poly(3-
hexylthiophene-2,5-diyl) (P3HT) as the active semiconducting layer and
poly(vinylphosphonic acid-co-acrylic acid) (P(VPA-AA)) as the polyanionic electrolyte
insulator.
Fig 2.a Schematic diagram of an electrolyte-gated transistor

13. Fig .b output characteristics of electrolyte-gated transistor.
Fig .c transfer characteristics of electrolyte-gated transistor.

14. This heat-gated transistor is operated by integrating the two devices in series the working
electrode of the thermoelectric generator is connected to the transistor gate electrode,
while the second ITESC electrode is connected to the source electrode (grounded)
Figure The structure of the ionic thermoelectric gated transistor

15. (a). Output characteristics at different fixed
gating ΔT (b). Transfer characteristics (C).
Output current tracking with the variation of ΔT

16.  This converts a modulation in ΔT to a
modulation in the drain current ΔI.
 The high ionic Seebeck voltage of the polymer
electrolyte is about 100 times larger than the
typical Seebeck voltage of electronic
thermoelectric materials.
 According to the study temperature sensing
amplification of ITGOT is 100 of times superior
to that of a single thermoelectric leg in
traditional thermopiles.

17.  Very High Seebeck coefficient found in polymer electrolytes
(∼10,000 μV K−1) .
 High Transconductance.
 High stability in output.
 High sensitivity (100 time to traditional thermoelectric material )
 Very High output voltage for small change in Temp.
 Material required are neither expensive ,rare nor hazardous.
 They do not operate at high frequency, they may find applications in
important low-frequency range (0.005–0.05Hz) of technology.

18. The heat-driven transistor
opens the possibility of many
new applications such as
 Sensing small temperature
Difference.
 Thermography
 Thermometry
 Electronic-skins.
 Photonics.

19.  Using functional medical dressings in which the
healing process can be monitored
 Use in heat cameras .
 One sensor can be combined with one transistor to
create a “smart pixel”.
 A matrix of smart pixels can then be used, for
example, instead of the sensors that are currently
used to detect infrared radiation in heat cameras.
 With more developments, the new technology can
potentially enable a new heat camera in your mobile
phone at a low cost.

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