Part 7 PIEZOELECTRIC EFFECT (PIEZOELECTRIC MATERIALS) & PHOTOMECHANICAL MATERIALS

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

Alphabetical list of materials, effects etc. mentioned on these pages:

Smart Materials Science INDEX * Carbon fibres * Chromogenic materials * Electrochromic materials * Gore-Tex * Halochromic materials  * High performance polymers * Kevlar * Lycra * Magnetic shape memory alloys * Magnetostrictive materials * Nitinol * pH sensitive polymers * Photochromic materials * Photomechancal materials * Piezoelectric effect materials * PTFE * Self-healing materials * Shape memory alloys * Shape memory polymers * Spandex * Teflon * Temperature responsive polymers * Thermochromic materials * Thinsulate

See also A general survey of materials - natural & synthetic, their properties & uses

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.

  ---

  T

  Doc Brown's School Science Website

  OP OF PAGE

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

and A general survey of materials - natural & synthetic, their properties & uses

TOP OF PAGE

Website content © Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Exam revision summaries & references to science course specifications are unofficial.

 Doc Brown's Chemistry 

*