1. WELCOME

2. TECHNICAL SEMINAR ON
“SMART MATERIALS”

3. INTRODUCTION HISTORY OF SHAPE MEMORY ALLOYS:
The first reported step towards discovery of shape memory effect were taken in 1930’s according to Otsuka and Wayman In a silver-cadmium alloy.
Shape memory polymers have also been developed and become commercially available in late 1990’s.
INTRODUCTION:
Shape memory alloys or SMA's are metals that exhibit shape memory properties.
It allows materials possessing shape memory properties to return to their original shape after having suffered some form of deformation after they are heated to temperatures above their transformation temperature.

4. What are Smart Materials?
Senses a stimulus (eyes).
Takes an intelligent decision (brain).
Through electronic feedback it takes corrective/preventive measures to avoid catastrophic situations (arm).

5. DEFINITION OF SMART MATERIALS:
Smart materials are materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, ph, electric or magnetic fields.

6. TYPES OF SMART MATERIALS
Shape memory alloys
Piezoelectric materials
Magnetostrictive materials
Active fluids
Ph and temperature sensitive polymers.

7. SHAPE MEMORY EFFECTS ONE WAY EFFECT: TWO WAY EFFECT:
TWO TYPES OF COMMON EFFECTS ARE:
ONE WAY EFFECT
TWO WAY EFFECT
ONE WAY EFFECT:
When a shape memory alloy is in its cold state, the metal can be bent or stretched and will hold those shapes until heated above transient temperature. Upon heating the shape changes to its original.
TWO WAY EFFECT:
A Material That Shows Shape Memory Effect During Both Heating And Cooling Is Called “Two Way Shape Memory”
INITIAL STATE
DEFORMED SHAPE
HEATING
BACK TO ORIGINAL SHAPE

8. PIEZOELECTRIC MATERIALS
Expand and contract with the application of voltage.
Piezoceramics are the most widely used smart material.
Applications
Ink Jet Printers.
Medical Diagnostics.
High frequency stereo-speakers.
Computer Keyboards.
Microphones.

9. MAGNETOSTRICTIVE MATERIALS
Expand and contract with the application of magnetic fields.
Applications
High-power sonar transducers.
Motors.
Hydraulic actuators.

10. ACTIVE FLUIDS
Respond to an electric or a magnetic field with a change in viscosity.
Applications
Tunable dampers.
Vibration-isolation systems.
Clutches.
Brakes.
Resistance Controls

11. pH AND TEMPERATURE SENSITIVE POLYMERS
pH-sensitive polymers are materials which swell/collapse when the pH of the surrounding media changes.
Temperature-responsive polymers are materials which undergo changes upon temperature.
Used as surface modifiers , drug delivery.

12. APPLICATIONS :
Activate control inceptors using smart material motion control.
Remove toxic pollutant from water.
Advanced liquid crystal display.
Artificial muscles.
Hydraulic fitting.
To determine the defects in buildings and bridges.
To find stealth in aeroplanes and submarines.

13. ADVANTAGES : BIO-COMPATIBILITY STRONG , CORROSIVE RESISTANT
PRODUCES VERY LARGE RECOVERY STRESSES
MATERIAL IS DUCTILE
VERY EFFECTIVE FOR LOW FREQUENCY VIBRATIONS

14. DISADVANTAGES : Expensive to manufacture. Slow reaction time.
Non linear thermo-mechanical behavior can limit the accuracy.
Low energy efficiency conversion.

15. CONCLUSION:
“ Smart materials” are just starting to emerge from the laboratory but soon you can expect to find them in everything from laptops to concrete bridges.

16. THANK YOU
PRESENTED BY :
ANANTH KR
SHIVARAJ N