The document describes Oonnittan Jacob's work developing thermoelectric devices for structural composites. It includes SEM images of a thick film bulk nanostructured thermoelectric device and diagrams of a multi-functional embedded thermoelectric structural composite. The document also summarizes projects involving composite fabrication, furnace design, sputtering target manufacturing, and retrofitting a hot press with a vacuum chamber.

1. Portfolio
Oonnittan Jacob

2. Development of thermoelectric devices for
structural composites
Ceramic plate
Thermoelectric module
p - type thermoelectric
n - type thermoelectric
Structural Composite
Ceramic plate
Concept : Multi-functional embedded thermoelectric structural composites; thermoelectric
module attached onto composite
These structural polymer matrix composites can be used as liners in furnaces, structural
panels, reinforcements as sound barriers on highways to harvest waste thermal energy

3. Thermoelectric devices for structural
composites
12 mm
800 ������m
SEM image (Top) of the Scaled up 2-inch diameter version of the
thick film bulk thermoelectric device
nanostructured
thermoelectric device
Part of thermoelectric
thick film bulk
nanostructured device
manufactured using the
pioneering method

4. Thermoelectric device development procedure
Testing and
characterization
Base elemental tests
powder (SEM/EDS, XRD,
DSC/DTA, TEM)
Nano structuring and alloying
using ball milling
Measurements Inert atmosphere
& sintering using
Characterization hot press and dc
power source
Bulk nanostructure device Alloyed powder
obtained post sintering (Grain size :10nm-15nm

5. Composite Projects
Starting carpet sample VARTM (Vacuum Assisted Resin Final composite
Transfer molding) process sample
Carbon fiber prepregs
incorporated with
modified resin system
containing POSS
nanoparticles
Fabricated filament wound
carbon/epoxy tanks

6. Miscellaneous Projects

7. Muffled Furnaces
Muffled furnaces capable of going to high temperatures. These were completely designed
and assembled in the lab for annealing samples. The temperature range of these
furnaces are from room temperature to 900°C (Big furnace) and 500°C (small furnace)

8. Sputtering Target and Copper cup
The picture shows a house made sputtering
target.
Manufactured the sputtering target from
nanostructured ball milled elemental powders.
Alloy formation completed in Induction furnace
and obtained polycrystalline ingot.
The target material is thermoelectric
semiconductor material of Bismuth Antimony
Telluride. Since the thermal conductivity of these
materials are low, they were housed in a house
fabricated copper cup and bonding carried out
using Indium

9. Cold chuck for Sputtering machine
The deposition of Aluminum Nitride was a challenge, the present wafer head did not have
cooling ability. We had to maintain low temperatures during the deposition as localized
heating of the wafer was drastically affecting the properties of the thin film. A lab mate and
myself designed and fabricated a cold head completely.
The cold head housed near the sputtering machine.
It uses glycol as coolant and goes up to -30°C .

10. Some pictures during intermittent stages
Channels milled for coolant Head TIG welded Head fitted with outlet and inlets Insulator bushings
Lid for sputtering chamber
Electrical & coolant connections TIG welding
Vacuum sealing and o-rings fitted together
Assembly Assembly

11. Retrofitting Hot Press with Vacuum chamber
Present CARVER hot press used in the lab does not have a vacuum
chamber. This drastically affects the properties of materials because
of oxidation at very high temperatures of 1000°C. Therefore
retrofitting it with a vacuum chamber.
Metal plates are glued together with Loctite
glue to carry out welding.
The vacuum chamber is designed to handle
• 10^-4 torr vacuum
•1000 kg

12. Other parts of the of the vacuum chamber fabricated from raw materials include:
Pressing rod
Plunger
Cooling Water jackets
 Outer sleeve
Pressing plates

13. Equipments used
Lathe
TIG welding machine
Milling machine