NEMS thermal switch operating based on thermal expansion of carbon nanotubes

• Design and simulation of a carbon nanotube-based thermal switch is reported.
• Thermal expansibility of the carbon nanotube is used to design a thermal switch.
• Electrostatic load is used to adjust the thermal switch trigger level.
• Temperature rising causes the pull-in instability and triggers the nano-switch.

In this paper, design and simulation of carbon nanotube-based thermal switches is reported. A carbon nanotube placed over a ground electrode represents the switch. The response of the nanoswitch based on beam theory is studied. When a nanotube has fixed–fixed boundary conditions, rise in temperature and thermal expansion of the nanotube can cause compressive axial load. This axial load will result in change of the pull-in voltage. Considering this fact, a thermal switch is designed for specific ambient temperature range and limited temperature rise range. When the temperature rises, the nanotube deflects more and approaches its pull-in instability. If temperature exceeds the threshold, pull-in occurs and the switch is triggered. Applying different voltages can provide different temperature thresholds. Utilizing this feature, the corresponding adjusting voltages required for actuating the switch by different rises in temperature are obtained.