Ultra high pressure sensing using graphene

Thin-film MEMS sensors are extremely useful for pressure sensing due to their high sensitivity, high-pressure range, and compact size. The sensitivity of MEMS pressure sensors strongly depends on the membrane thickness [1]. Atomically thin 2-D materials are the foremost contenders that are expected to replace conventional membranes in the near future. Graphene is one of the prime contender amongst them due to its high sensitivity, high elastic limit, high adhesivity, and impermeability to gases [1,2].

At present, the size of pressure sensors has approached the sub-micron scale, which motivates us, in this work, to explore the pressure-sensing characteristics of graphene in nano-electro-mechanical systems (NEMS). This work uses the thin-film approximation to calculate graphene's critical pressure on various substrates along with the membrane theory to calculate its deflection and pressure sensitivity.  This work shows that the graphene’s pressure sensitivity depends only on its radius, while the pressure range depends on its radius and adhesivity.  From the results, we infer that graphene can be used to design highly sensitive NEMS pressure sensors with an ultra-high-pressure range (~10⁹ Pa) in the nanoscale regime.

 

References: 

 

 1. Smith, A. D., et al., Nano letters 13.7 (2013): 3237-3242.

 

2. Koenig, S. P., et al., Nature Nanotechnology 6.9 (2011): 543-546.