Active micromixers - Micromixers Fundamentals Design and Fabrication - page 240

FIGURE 7.1
Characteristics of microactuators used in active micromixers: (a) typical actuation magnitudes; (b) typical
actuation frequency.

1
2 E mech ð

2

e ¼ a th D T Þ (7.1)

where E mech and a th are the Young's modulus and the thermal expansion coefficient of the actuator's
material.

T is the temperature difference.
The energy density of a piezoelectric actuator is proportional to the electric field strength E el and
inversely proportional to the piezoelectric coefficient d and the Young's modulus E mech :

D

E el

1
2

e ¼

2 :

(7.2)

ð dE mech Þ

The energy density in an electrostatic actuator is equivalent to the electric energy stored in the
capacitance between the two electrodes:

1
2 3E el

e ¼ (7.3)

where e is the permittivity of the material between the two electrodes.