Piezoelectric crystals Crystals that are centred around piezoelectricity

Piezoelectric crystals Crystals that are centred around piezoelectricity. Chisara and Beatrice

What is Piezoelectricity • It’s a Charge!! It happens… • When certain solid materials such as crystals and some ceramics are struck they generate an electric CHARGE • Advantages The crystals can generate a high voltage without being connected to a local power source. They are energy efficient. • Disadvantages The crystal can crack if over stressed and may pick up stray voltages in other wires which may result In the product malfunctioning.

What type of crystals? • Man made such as man made quartz • Naturally occurring Cane sugar, Quartz, Topaz, Rochelle salt. These all exhibit PEIZOELECTRICITY

Uses • Quartz clocks: The electrical current and vibration produces pulses which are counted to keep time. • Radios • Computers • Acoustic instruments: The crystal is able to both produce and capture sound through the vibrations of the electrical current. INSIDE A QUARTZ CLOCK • Battery provides current to microchip circuit • Microchip circuit makes quartz crystal generate electrical impulses • Microchip circuit detects the crystal's oscillations and turns them into regular electric pulses, one per second. • Electric pulses drive miniature electric stepping motor. energy into mechanical power. • Electric motor turns gears.

Piezoelectric materials create electrical charge when mechanically stressed

And an applied electrical field can cause them to change their shape or dimensions. Electricity

They are natural materials such as Quartz, barium titanate and cadmium sulfide z t r a u Q

Piezo electrics in use…. The following picture shows a vehicle classification sensor. Piezo electrics are used here to weigh moving vehicles…. A piezo electric material is encased in aluminium housing and the connected to a computer which interprets the data recorded.

Another use of piezo electrics is an acoustic transducer A piezoelectric acoustic transducer is attached to the side of this guitar. The transducer converts the sound produced by the Guitar into an electrical signal This signal is then amplified and is broadcast over loud speakers

Medical Ultrasound Imaging Transducers Piezo Ink Jet Heads Automotive Knock Sensor, Geophones, Hydrophones Tank Gauging