Shabaz over at Element14 writes:
This post is about an interesting, low-cost sensor that doesn’t need much processing to use, and has some unique characteristics – a PVDF (polyvinylidene difluoride) Piezoelectric sensor. The sensors looks like a small strip of plastic, and can be used for detecting movement or vibrations even into ultrasound. Such devices can help sense in many practical, real-world scenarios. They are extremely sensitive, low cost and easy to use. Some simple practical experiments with these sensors are described, finally looking at detecting ultrasound.
Impact, vibration and ultrasound sensing with PVDF Piezo sensors - [Link]
Researchers Steve Dunn at Queen Mary University and James Durrant at Imperial College London have been experimenting with a new design of thin, flexible solar cell made from zinc oxide. Manufacturing costs of the new cells will be significantly lower than conventional silicon based technology. The only disadvantage is their poor efficiency; just 1.2 %, a fraction of that achievable with silicon.
The material also exhibits piezo-electric properties, nanoscale rods of the material generate electricity when they are subjected to mechanical stresses produced by sound wave pressure. Sound levels as low as 75dB, equivalent to that from an office printer, were shown to improve efficiency. Durrant said “The key for us was that certain frequencies increased the solar cell output, we tried our initial tests with various types of music including pop, rock and classical”. Rock and pop were found to be the most effective. Using a signal generator to produce sounds similar to ambient noise they saw a 50 % increase in efficiency, rising from 1.2 % without sound to 1.8 % with sound.
New Solar Cell Shows a Preference for AC/DC - [Link]
by Publitek European Editors
There are many different types of accelerometers for industrial applications, ranging from the latest micro-machined capacitive devices to traditional rugged piezo electric crystals. The boom in portable devices and the advantages of knowing the position and orientation of the equipment, as well as the increased use of accelerometers in vehicle air bags, has led to an explosion in the different types of devices in recent years. All of this is to the advantage of the engineer who can use the wide range of devices for different applications, from monitoring to position measurement.
Sensor Technologies for Accelerometers - [Link]
If you´re searching for a piezo transducers, buzzer, siren or a loudspeaker with a high efficiency and a high reliability, you´re on the right address. Narrow specialization, long-term know how, many patents and an own “in-house” production make the company Sonitron a European leader in a segment of piezo components.
An absolute majority of Sonitron components is resistant to harsh environment, dust and gases. In the offer we can find many types usable in critical applications (medical, military and other). Thanks to this fact, Sonitron also supplies such customers like for example NATO, Volvo and AirBus.
Directly from our stock, we´re able to provide you with many piezo components – piezo elements (transducers, without a driver) but also with drivers (sirens, buzzers) usually working in a very wide voltage range (for example 2-35V). A more detailed description of a piezo technology and description of products can be found in the Sonitron catalogue (25MB).
In case of interest even in non-stock types, please contact us at firstname.lastname@example.org.
Sonitron – piezo transducers, which you can rely on – [Link]
This instructable will guide you through creating your own Arduino based Kitchen Timer. This is a quite simple project, requiring little or no programming or electronics knowledge, just the willingness to learn and fiddle – an ability most useful for modern man.
This kitchen timer is simple enough, press and hold a button and it will count up it multiples of five minutes, until you release the button. Upon doing so the timer will flash, and begin counting down. This timer includes an alarm and a display, with a piercing piezo buzzer to get your attention.
The arduino, laptop, protoshield, and USB Cable excluded; I took every electrical component from an old or broken device. Try to recycle things, its easy to get hold of broken electronics for free so make the most of it! See any jumpers on this design? No, paper clips are much better – cheap as chips and more sturdy too!
Arduino Kitchen Timer - [Link]
Piezoelectric materials are about as close to magic as you can get. They turn physical pressure into electricity and can even turn electricity into physical pressure – an amazing sort of bidirectional converter for mechanical and electrical energies. Perhaps even more amazing is the fact that you can easily ‘grow’ your own piezoelectric crystals overnight using just a couple of common ingredients – awesome.
Collin’s Lab: Homebrew Piezo - [Link]
This circuit is a Dark Detector using a 555 timer IC. The 555 is configured as an astable oscillator to drive the piezo buzzer. Check circuit diagram on the link below.
“Dark Detector” using a 555 timer IC – [Link]
The objective of this project is to use inexpensive PIR sensor to detect if a human has moved. To build this project I use a PIC18F25K20 microcontroller to detect if the sensor had change state and it will emit a sound from the speaker or piezo, the MCU also detect the voltage of the battery in the startup, the algorithm it´s very simple it use an interrupt on change to detect the change on the PIR sensor.
PIR Motion Sensor - [Link]