Design of a graphene capacitive pressure sensor for ultra-low pressure detection

This paper reports the design and theoretical calculation of a capacitive ultra-low pressure sensor, which is based on circular suspend graphene diaphragm array. The atom scale thickness and high mechanical strength of suspend graphene diaphragm both contribute to ultra-low pressure measure range. As the size of single suspend graphene diaphragm is limited by fabrication process, a parallel connected sensor array is designed to achieve detectable capacitance change and redundancy. In calculation, a sensor array with 40,000 5μm radius suspend graphene diaphragm cells in 4mm×4mm size can provide 288fF/Pa sensitivity to pressure load.