High-Sensitivity GNPs/PDMS Flexible Strain Sensor with a Microdome Array

In this research, polydimethylsiloxane (PDMS) and graphene nanoplatelets (GNPs) were used as flexible substrates and conductive layers. A facile and template transfer method combined with a low-cost solution-spraying process was adopted to prepare the microdome array GNPs/PDMS flexible strain sensor. The microdome array produces different degrees of in-plane deformation and the gradient distribution of the GNP conductive network on the surface during stretching. This affects the contact effect between the adjacent cells of the GNP conductive network on the film surface in different strain ranges, thereby realizing a sensitive resistance response. The strain sensor of the microdome array GNPs/PDMS exhibits excellent gauge factors (GF) of 8.98 (0.26% < ε < 20%), 18.31 (20% < ε < 43%), and 34.57 (43% < ε < 60%), the highest of which is 8 times higher than that of the planar GNPs/PDMS strain sensor without a microdome array. In addition, the material exhibits remarkable stability and durability (10 000 cycles), fast response time (125 ms), and stable relative frequency/strain sensing performance. Finally, the strain sensors of the microdome array GNPs/PDMS were packaged for various application tests, showing broad application prospects in electronic skin, wearable electronic devices, and component health monitoring.