Doc Brown's Chemistry Revision Notes - Smart Materials and Materials Science

Part 7 PIEZOELECTRIC EFFECT (PIEZOELECTRIC MATERIALS) and PHOTOMECHANICAL MATERIALS


ALPHABETICAL LIST of materials, effects etc. mentioned on these pages: Smart Materials Science INDEX * CARBON FIBRES * CHROMOGENIC MATERIALS * ELECTROCHROMIC MATERIALS * GORETEX * HALOCHROMIC MATERIALS  * HIGH PERFORMANCE POLYMERS * KEVLAR * LYCRA * MAGNETIC SHAPE MEMORY ALLOYS * MAGNETOSTRICTIVE MATERIALS * NITINOL * pH SENSITIVE POLYMERS * PHOTOCHROMIC MATERIALS * PHOTOMECHANICAL MATERIALS * PIEZO ELECTRIC EFFECT-MATERIALS * PTFE * SELF-HEALING MATERIALS * SHAPE MEMORY ALLOYS * SHAPE MEMORY POLYMERS * SPANDEX * TEFLON * TEMPERATURE-RESPONSIVE POLYMERS * THERMOCHROMIC MATERIALS * THINSULATE *


Part 7a. PIEZOELECTRIC EFFECT and PIEZOELECTRIC MATERIALS

  • Piezoelectric materials are materials that produce a tiny voltage when stress is applied e.g. pressure by compressing a material i.e. 'squeezing' it.

    • The electric polarising effect is a direct result of mechanical stress on the crystal structure of the material.

      • Piezoelectricity is observed in some anisotropic (no centre of symmetry) crystals when subjected to mechanical strain.

    • Piezoelectric materials are most widely used as sensors in different environments.

    • This piezo-electric effect can be used to detect stress and deformation in solid materials.

    • The effect can used in general to detect pressure changes in gases or liquids i.e. pressure transducers and other electrical instrumentation components.

    • The piezoelectric effect is used in lighters.

  • The effect can work in the opposite way and an applied electric field (p.d. voltage) across the material will produce stress within the sample and cause it to change shape.

    • This reverse phenomenon is known as the electrostrictive or motor effect.

    • Therefore structures can be designed and made to bend, expand or contract when a voltage is applied for a particular use.


Part 7b. PHOTOMECHANICAL MATERIALS

  • PHOTOMECHANICAL MATERIALS are involved in any process by which a printing surface is prepared mechanically with the aid of photography.

  • Photomechanical materials can change shape under exposure to light.


WHERE NEXT?

INDEX of SMART MATERIALS PAGES

PART 1 CHROMOGENIC MATERIALS - Thermochromic, Photochromic & Electrochromic Materials

PART 2 SHAPE MEMORY ALLOYS e.g. Nitinol & Magnetic Shape Memory Alloys

PART 3 SHAPE MEMORY POLYMERS, pH and temperature sensitive-responsive polymers, Self-healing materials

Part 4 LYCRA-SPANDEX

PART 5 High performance polymers like KEVLAR

PART 6 GORETEX, THINSULATE and TEFLON-PTFE

PART 7 PIEZOELECTRIC EFFECT (PIEZOELECTRIC MATERIALS) and PHOTOMECHANICAL MATERIALS

PART 8 CARBON FIBRES

See also INDEX NANOSCIENCE-NANOCHEMISTRY pages

Nanomaterials including carbon nanotubes, carbon fibres and silver nanoparticles are on a separate page

More on chemistry applications: Uses of 220+ chemical elements, compounds, mixtures & Formulation chemistry

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