Piezoelectric effect refers to the ability of certain materials to produce electric polarization under applied mechanical stress. This electric polarization manifests as a measurable potential difference across the material. One of the unique characteristics of the piezoelectric effect is the reversibility: electric polarization under applied stress, and the generation of stress under an electric field. This self-driven piezoelectric disc combines both effects. A piece of electronically isolated piezoelectric ceramic is assembled on the top of the metal plate to work as the feedback electrode (see picture above).

Upon the activation of the main piezoelectric element (large ceramic section), the metal diaphragm contracts and expands alternately, resulting in a voltage generated across the isolated piezoelectric ceramic. One main advantage of the self-driven piezoelectric disc is that the feedback signal can be used to create a closed-loop control circuit. A typical oscillation circuit is shown above.

Key Features

Self-drive
Reversible high-frequency response
Adaptable to various applications
Low power consumption
Actuation frequency: 2- 6.6 KHz
Operating voltage: Max 60 V_p-p
Different metal plates available, including Ni, Brass, and stainless steel
Compact size: 12.0 mm to 35.0 mm in diameter
Lightweight
Custom design capability

Piezoelectric materials are widely used in compact actuators such as linear motors, rotary motors, pumps in inkjet printers, and sensors such as pressure sensors and load cells. In microfluidic devices or lab-on-a-chip systems, the direct piezoelectric effect is used in micro-scale chemical and biological sensors. For example, high-precision mass measurement devices are used to measure the weight of biological cells or molecules based on resonant frequency shifts experienced by the piezoelectric resonators. Acoustic transducer use piezoelectric materials to generate sound waves that have been used in biological cell manipulation, such as cell focusing and sorting.

Part Number	Frequency (kHz)	Impedance (Ω)	Capacitance (pF)	Plate Material	Plate Diameter D (mm)	Piezo Diameter d (mm)	Total Thickness T (mm)
SPEC-001	5.8±0.5	≤600	12000±30%	Ni	ɸ10.0±0.20	ɸ9.0±0.2	0.12±0.05
SPEC-002	5.8±0.5	≤600	12000±30%	Ni	ɸ12.0±0.15	ɸ9.0±0.2	0.12±0.05
SPEC-003	4.0±0.5	≤350	23000±30%	Brass	ɸ12.0±0.15	ɸ15.0±0.3	0.28±0.05
SPEC-004	6.6±0.5	≤400	10000±30%	Brass	ɸ20.0±0.20	ɸ15.0±0.3	0.42±0.05
SPEC-005	2.0±0.5	≤800	45000±30%	Brass	ɸ20.0±0.20	ɸ20.0±0.3	0.23±0.05
SPEC-006	2.8±0.5	≤500	50000±30%	Brass	ɸ27.0±0.20	ɸ20.0±0.3	0.32±0.05
SPEC-007	3.8±0.5	≤300	20000±30%	Brass	ɸ27.0±0.20	ɸ20.0±0.3	0.42±0.05
SPEC-008	4.0±0.5	≤500	20000±30%	Brass	ɸ27.0±0.20	ɸ20.0±0.3	0.45±0.05
SPEC-009	4.5±0.5	≤500	20000±30%	Brass	ɸ27.0±0.20	ɸ20.0±0.3	0.50±0.05
SPEC-010	2.6±0.7	≤300	30000±30%	Brass	ɸ35.0±0.20	ɸ25.0±0.3	0.48±0.05