High Sensitivity Flexible Electronic Skin Based on Graphene Film

Abstract

Electronic skin with high sensitivity, rapid response, and long-term stability has great value in robotics, biomedicine, and in other fields. However, electronic skin still has challenges in terms of sensitivity and response time. In order to solve this problem, flexible electronic skin with high sensitivity and the fast response was proposed, based on piezoresistive graphene films. The electronic skin was a pressure sensor array, composed of a 4 × 4 tactile sensing unit. Each sensing unit contained three layers: The underlying substrate (polyimide substrate), the middle layer (graphene/polyethylene terephthalate film), and the upper substrate bump (polydimethylsiloxane). The results of the measurement and analysis experiments, designed in this paper, indicated that the flexible electronic skin achieved a positive resistance characteristic in the range of 0 kPa–600 kPa, a sensitivity of 10.80 Ω /kPa in the range of 0 kPa–4 kPa, a loading response time of 10 ms, and a spatial resolution of 5 mm. In addition, the electronic skin realized shape detection on a regular-shaped object, based on the change in the resistance value of each unit. The high sensitivity flexible electronic skin designed in this paper has important application prospects in medical diagnosis, artificial intelligence, and other fields.

Graphene Nanostructure-Based Tactile Sensors for Electronic Skin Applications

“…5c. To realize the spatial resolution of a tactile sensor, a pressure sensor array with a 4 × 4 tactile sensing unit was constructed by Lv et al, and each sensing unit contained a polyimide (PI) substrate, CVD graphene/PET film and PDMS substrate bump [63]. The authors believed that the designed high-sensitivity flexible E-skin might have important application prospects in medical diagnosis, artificial intelligence, and other fields.…”

Applications of Graphene-Based Materials in Sensors: A Review

“…The picture of the sensor is shown in Figure 2d1,e1. The principle is that the piezoresistive effect of graphene material is used When under pressure, the C-C bond will differentiate or break, resulting in the change of resistivity of graphene film [59,60]. Since graphene film has excellent sensitivity and (b1) Preparation process of a sensor made of conical microstructure PDMS substrate and double-layer graphene [58]; (c1) Sensitivity curve of the sensor with and without conical microstructure [58]; (d1) Structure and enlarged details of electronic skin [59]; (e1) Size and photos of electronic skin [59].…”

“…The principle is that the piezoresistive effect of graphene material is used. When under pressure, the C-C bond will differentiate or break, resulting in the change of resistivity of graphene film [59,60]. Since graphene film has excellent sensitivity and flexibility, the sensor has high sensitivity [59].…”

“…Flexible pressure sensor. (a1) Manufacturing process diagram of LIG/CCG sensor[52] (b1) Preparation process of a sensor made of conical microstructure PDMS substrate and double layer graphene[58]; (c1) Sensitivity curve of the sensor with and without conical microstructure[58]; (d1) Structure and enlarged details of electronic skin[59]; (e1) Size and photos of electronic skin[59].…”

Developing Wound Moisture Sensors: Opportunities and Challenges for Laser-Induced Graphene-Based Materials

“…While LIG scribed directly onto a substrate can undergo bending motion, stretching is much more problematic-with physical extension leading to fragmentation and circuit breaks. There have been attempts to address such limitations with serpentine designs or the transfer of the LIG from conventional PI to elastomeric substrates such as silicone or polyurethane [60][61][62]. It is important to note that the actual size of the sensing component itself can be very small (in the order of millimetres) and it could be envisaged that, when placed within a dressing, this component could remain relatively unperturbed by motion in the underlying skin-it is the track connections to the external monitoring device that are liable to be affected.…”