Continuous graphene and carbon nanotube based high flexible and transparent pressure sensor arrays

Abstract

The transparent pressure sensing arrays durable to severe deformation are fabricated by covering the continuous graphene sheets on the tip of thermal plastic polyurethane (TPU) pyramids, while most of the TPU surface is covered by a layer of densely entangled single wall carbon nanotubes. The transparency of the conducting layer exceeds 91%. The capacitance variations between TPU surface and flat electrode under compressive deformation show high sensitivity and a broad dynamic range from hundreds Pa to MPa. The measured capacitance variations show high load sensitivity and stability under repeated deformation cycles. Finite element numerical simulations present that the contact area change under deformation increases the capacitance variation. The high stability of the capacitance response to fluctuated loads demonstrates that graphene layer on the surface of TPU pyramids maintains the continuity of electric contact under a large deformation ratio and high repeating cycles. 16 × 16 arrays are connected to a circuit and a typical load distribution is regenerated by mapping the local capacitance variations on the arrays with sub-minimeter spatial resolution.

Stretchable, Transparent, and Self‐Patterned Hydrogel‐Based Pressure Sensor for Human Motions Detection

“…Inset is a photograph of the hydrogel film against blue background. f) Transmittance and maximal strain comparison of reported soft electronics with the pressure sensor …”

Flexible Sensors—From Materials to Applications

“…Finite Element Analysis (FEA) has been the most common numerical method used for simulations, specially using commercial software such as Abaqus [136,451,[568][569][570] or Comsol [571][572][573][574]. These tools have been used to better understand the mechanical behaviour of the sensors prior to the fabrication [568], perform parametric analysis of geometries under adverse mechanical loadings [22,136,[569][570][571], understand electrical behaviour of the components [569,[573][574][575], and to analyze the electrical response under a deformed state [569,573]. Besides, numerical simulations have been proved to be a practical tool in the analysis of changes in capacitance with the effect of strain [576] and for the analysis of electrical performance and mechanical stability of flexible circuits with different configurations under bending loads [572].…”

Evaluation Strategies of Nanomaterials Toxicity

“…Commonly, nanomaterials have different shapes and structures such as tubes, fibers, spheres, and planes. For instance, several studies compared cytotoxicity of multi-wall carbon nanotubes vs. singlewall carbon nanotubes or graphene [9,10], obtaining results that suggest a strong influence of the shape and toxicity. Furthermore, other authors have evaluated the toxicity of nanocarbon materials vs. NPs [11].…”