Sensitive capacitive pressure sensors based on graphene membrane arrays

The high flexibility, impermeability and strength of graphene membranes are key properties that can enable the next generation of nanomechanical sensors. However, for capacitive pressure sensors, the sensitivity offered by a single suspended graphene membrane is too small to compete with commercial sensors. Here, we realize highly sensitive capacitive pressure sensors consisting of arrays of nearly ten thousand small, freestanding double-layer graphene membranes. We fabricate large arrays of small-diameter membranes using a procedure that maintains the superior material and mechanical properties of graphene, even after high-temperature annealing. These sensors are readout using a low-cost battery-powered circuit board, with a responsivity of up to $$47.8$$  aF Pa−1 mm−2, thereby outperforming the commercial sensors. Arrays of tiny graphene membranes exhibit excellent performance as pressure sensors, offering a competitive, low-cost alternative to commercially available systems. Graphene offers a durable and resilient material for sensors that generate a capacitive readout to pressure changes, but individual membranes are not sufficiently sensitive. Researchers led by Makars Siskins and Peter Steeneken of the Delft University of Technology in the Netherlands have devised a strategy for fabricating graphene sensor arrays that overcome this limitation. Their method yields millimeter-scale assemblies of 10,000 double-layered graphene membranes, which can in turn be connected to an inexpensive battery-powered circuit board. The authors demonstrate that this system can outperform a state-of-the-art commercial pressure sensor, and propose that further improvements to the design and fabrication of these arrays could improve their responsiveness by a full order of magnitude.