30 Development of Electrostatic Linear Motor for Insect-Type …
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handle wafer. A layer of 100 nm-thick aluminum is deposited on the device-layer
silicon to energize. The active part of the motor was floated by etching buried oxide.
Figure 30.7 shows the electrostatic motor. The electrostatic motor chiplet
measures approximately 2.2 mm × 2.5 mm. The electrostatic motor is composed of a
shuttle at the center, a coupler at the shuttle, four electrostatic actuators deployed two
pairs for pushing the shuttle, arms deployed at the tip of the electrostatic actuators,
main spring and sub spring that return to the original position, electrodes V D1 , V D2 ,
and GND. An electrostatic motor produces linear motion of the shuttle by energizing
the electrodes.
30.4.2 Leg Drive Experiment by the Electrostatic Motor
Figure 30.8 shows the driving circuit of the electrostatic motor. The resistance value
is R 1 = R 2 = 2.2 M. The transistors were switched using a waveform generator to
generate drive waveforms V D1 and V D2 . Figure 30.9a is the driving waveform using
a voltage source. The driving waveform is a square wave with a pulse width 10 ms,
pulse period 7.5 ms, pulse amplitude 60 V. Figure 30.9b is the driving waveform
using the PV cell array. The driving waveform of Fig. 30.9b occurred a voltage drop
Fig. 30.8 Driving circuit of
the electrostatic motor (Saito
et al. 2017)
Fig. 30.9 Driving waveform
of electrostatic motor (Saito
et al. 2017)