Desktop Fabricated Heatuators
Above is a Solid Works drawing of a thermal actuator or "heatuator". When
an electric current is passed through, the 15 m
wide "thin" arm gets hotter than the 60 m
wide "fat" arm, and therefore thermally expands more. This causes the actuator
to bend in the direction of the "fat" arm.
This device is manufactured out of 13 m
thick stainless steel sheet metal using the Microlaze
laser micromachining process.
Currents of up to 250 mA will actuate the heatuator. Already at 250
mA, the device glows red hot and will burn up if sustained.
Here is a picture of the heatuator before and after activating with
Following are short RealVideo clips of
the heatuator being actuated at various currents. They are shown in real
Heatuator at 100 mA
Heatuator at 150 mA
Heatuator at 200 mA
Heatuator at 250 mA. You can see the device
glowing red hot. The ambient illumination is changed twice during the clip
to show this. Also, at the end of the clip, the current is run continuously
until the device fails. You can see the thin arm is broken.
These videos show various currents being passed through a simple 15 m
thick arm. Because the arm is held between two stationary pads, its thermal
expansion causes it to bend up.
Simple arm at 300 mA
Simple arm at 375 mA
Simple arm at 375 mA. This clip has no
ambient illumination so you can see that the arm really does glow red hot
in the dark. At the end of the clip, the current is turned past 375 mA
(to around 400 mA) so that the device fails and breaks in the middle.
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