Modelling and experimental verification of heat dissipation mechanisms in an SU-8 electrothermal microgripper

• A microgripper is operated in ambient environments with varying thermal conductivities – different gases and pressures.
• The dominance of heat dissipation from the structure is emphasised by these experiments.
• Plots of opening distance vs drive current can be explained directly by the consideration of gas molecule mean free paths.

Within this work, a microgripper based on a hot–cold arm principle was tested to give a greater understanding of the associated heat dissipation methods. Experiments were conducted in air at atmospheric and sub-atmospheric pressure, and in helium, argon and helium at sub-atmospheric pressure. The change in deflection, when using gases with different thermal conductivities and at varying pressures showed the significance of conduction through the atmosphere. The experimental results were found to verify a theoretical model created previously by this group, and a further model developed independently; both predicted the deflection that a given current would cause.

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