Hell Suma,

In my opinion, you should select a piezo device with higher resonant frequency than your normal frequency of operation. That means if you are working at around 200kHz, look for something beyond that may be in the MHz range to be safer.

Another important to see as what displacement you are looking for the shaker to be achieve at this frequency.

And the third as whether you want a single device or a multiple of these devices combined together to achieve the said displacement.

Hi!

I completely agree with Professor Prasanna. If you are looking for a quasi-static resonator/ actuator, then I would suggest you to go for a higher resonant frequency. You can draw motivation for your question from the fact that the non- contact modes of operation of AFM cantilevers uses high resonant frequencies. Same is the case with cantilever based bio-sensors.

Hope I could help!

Thanks for your helpful reply Mr. Prassana and Mr. Mukherjee!

So far, I came across many piezoceramic actuators which are having a resonance frequency, less than 40kHz. I have a question here, can I combine 5, 40kHz piezoceramic actuators in order to obtain 200kHz of frequency bandwidth? (I am sorry, if I sound stupid. I am just 15 days old to this topic). I have to generate at least 10g's of acceleration out of it. The main purpose is to design a piezoceramic based vibration generator to test sensor.

Hi ,

the best choice for a shaker? In my opinion, it depends of the quantity and the power it requires to obtain a good emulsion. Take into account that generally higher is the frequency and ...lower is the power you may reach!!

Frequency in multi converter cannot be cumulative (i.e. using five 40kHz actuators the output of generator should remain at 40kHz, it increases only the sound pressure, ...if the five are well placed )

Hope that can help you!

Which kind of load do you want examine  with shaker in range up to 200kHz? For most electromechanical system the range up to 10kHz is enough. BTW pay attention that  resonance frequency doesn't define shaker bandwidth

Thanks for your reply Mr. Finezzo and Mr. Gannel. 

I have to develop a vibration generator using piezoceramic actuator to examine the sensor behavior at high frequencies, say 200kHz. So far, I have assumed that to achieve greater shaker bandwidth, I have to select an actuator that has high resonance frequency. If resonance frequency doesn't  define shaker bandwidth than what is the other factor that I have to check in order to get large bandwidth?

Can you share with us more details regarding type of sensor and application with it? Again high frequency is seems out of range for practical application...

  There are some manufacturers in Europe / Germany who are manufacturing piezo ceramic materials and actuators in various shapes and sizes. You can contact them to get further details. Another way is to use the actuators from ultrasonic cleaners if the frequency is in your range of interest.   Best Luck!

Suma,

If you want to study the sensor behavior at such high frequency as 200kHz, then I would suggest not to make or design your actuator or the shaker/vibrator on your own. In such requirements, it is always advisable to have a "STANDARD/REFERENCE" exciter or shaker/vibrator/actuator and then study the performance of your actual sensors.

Well, you can make your own actuator in any way but then you will have to "GET IT CALIBRATED" first with reference to some standard vibration exciter and then use to study the sensor behavior.

Sensor is used in airbag control system.

I have referred the existing one, it works up to 30kHz frequency and with high blocking force (3000N-13000N). It has attached with laser vibrometer, matching networks and DSP based control system in order to improve its performance.

Initially, I have to build a basic shaker/ vibration generator which operates up to 200kHz (bandwidth) or may be quite less and then to excite the sensor by placing it on top to analyze its characteristics.

I have to develop almost like the one I have attached.

Hello Suma,

The paper describes a sound subwoofer based actuator. They have also used a reference calibrated accelerometer with a typical frequency response upto 3kHz and the resonant frequency higher than 40kHz.

So first you should decide what frequency range you want to work ("....which operates up to 200kHz (bandwidth) or may be quite less .....") or whether the woofer based solution would be just sufficient for you.

I have been working with vibration control systems for some time now and I remember based on the concept of this loudspeaker/woofer we built our own EM shaker with good quality permanent magnets and the coil. The coil and amplifier were also built by us. But the frequency of operation was limited to few kHz. Even the commercially available electromagnetic shakers are rated for few tens of kHz. Therefore I am wondering as what frequency range you are exactly looking after?

In my opinion, you can build the simple exciter as like the woofer and then start testing with whatever the maximum frequency it can support for. Then you can think of extending the operational frequency. This will give you some idea about how your sensors are behaving.

As I said earlier, you can also use Ultrasonic transducers used in Medical U/S applications to excite at 100s of kHz. But choose from continuous wave rather than pulsed power ones.

I got it. Thanks for your helpful information Mr. Prassana Waichal..