Table 1 Dimensions and performance metrics of three different cellular electrostatic actuators based on measurements, calculations, and finite element analysis

Cell length

80 µm

80 µm

80 µm

Silicon sidewall width

3 µm

4 µm

4 µm

Polysilicon electrode width

5 µm

7 µm

7 µm

Device layer thickness

50 µm

50 µm

50 µm

Vertical displacement upon actuation voltage

304 µm

333 µm

678 µm

Actuation Voltage*

45 V

60 V

46 V

Flexural stiffness of device

3.4 N/m

14.2 N/m

1.8 N/m

Effective Young’s modulus

301 MPa

675 MPa

675 MPa

Bending moment

4.7 × 10⁻⁷ Nm

2.0 × 10⁻⁶ Nm

1.1 × 10⁻⁶ Nm

Curvature (R⁻¹)

0.18 mm⁻¹

0.14 mm⁻¹

0.08 mm⁻¹

Energy Density

0.7 mJ/cm³

1.42 mJ/cm³

0.47 mJ/cm³

Normalized Bending moment**

2.32 × 10⁻¹⁰ Nm/V²

5.5 × 10⁻¹⁰ Nm/V²

5.48 × 10⁻¹⁰ Nm/V²

Normalized Curvature (R⁻¹)**

0.09 m⁻1 V⁻²

0.04 m⁻¹V⁻²

0.04 m⁻¹V⁻²

Energy density***

1.7 × 10⁻¹⁰ J/cm³V⁴

1.05 × 10⁻¹⁰ J/cm³V⁴

1.05 × 10⁻¹⁰ J/cm³V⁴