Stretchable\nStrain Vector Sensor Based on Parallelly\nAligned Vertical Graphene

Abstract

The development of\nwearable strain sensors for the human–machine\ninterface has attracted considerable research interest. Most existing\nwearable strain sensors were incapable of simultaneously detecting\nstrain amplitudes and directions, and they failed to fully record\nstretching vectors that occurred on the body. Graphene and graphene-derived\nmaterials have been utilized to construct wearable strain sensors\nwith excellent electrical sensitivities. Although the growth techniques\nof planar graphene and vertical graphene (VG) have been established,\nthe fabrication of VG aligned in parallel within a larger area has\nnot been previously achieved. Here, parallelly aligned VG (PAVG) in\na large area was successfully fabricated and constructed as a wearable\nstrain vector sensor. The PAVG was fabricated via inductively coupled\nplasma chemical vapor deposition assisted by metal inducers. The as-fabricated\nsensor was electrically anisotropic because of the profiles of the\nVG nanosheets aligned in parallel. Therefore, the sensor could simultaneously\nand sensitively detect the direction and the amplitude of the strain\nvectors with excellent accuracy. Application of this strain vector\nsensor for the human–sensor interface to identify the stretching\ndirections and amplitudes of finger joints was also demonstrated.\nThis work established the fabrication methodology of graphene with\nunique vertical and parallel alignment morphology. This study introduced\na new opportunity of developing wearable sensors that could fully\ndetect multidirectional human actions.