I've been curious about methods of generating electrical current from kinetic energy and hadn't looked into the Piezoelectric effect before. So my understanding is that Piezoelectric materials create an electric current when they are deformed/displaced by a physical force, am I right in thinking that if I hook a multi-meter up to a quartz crystal and then hit that crystal with a rubber mallet that the multi-meter will show a increased current?

You will certainly get a signal.

But if you're looking to generate current you'd better investigate other means.

The piezo effect generates a voltage which drops off rapidly when current is drawn.

 

The resultant current depends upon impednace of the load.

A multimeter might not respond quickly enough to an impulse. An oscilloscope might be better for measuring the voltage response.

 

As MigL implies, these are inefficient devices for converting mechanical work into electrical energy.

A multimeter might not respond quickly enough to an impulse. An oscilloscope might be better for measuring the voltage response.

 

As MigL implies, these are inefficient devices for converting mechanical work into electrical energy.

 

 

I'm glad you mentioned the impulse. +1

 

It is the impulse not a steady force that generates the electricity.

 

Steady forces can produce triboelectricity.

 

https://www.google.co.uk/?gws_rd=ssl#q=triboelectricity

Piezo energy harvesters are already available:

https://www.piceramic.com/en/applications/energy-harvesting/energy-harvesting/

 

Some piezo-electric transducers can handle pretty low frequencies and can be considered "quasi-static", but it is true that they are more suited for higher frequencies.