Stretchable vertical graphene arrays for electronic skin with multifunctional sensing capabilities

How Far for the Electronic Skin: From Multifunctional Material to Advanced Applications

“…Mechanical stimuli can change the distance or the overlapping area between the two electrodes, and the change of distance and area can convert into capacitance change to realize pressure sensing. The acquisition of high sensitivity requires flexible electrode materials and dielectric materials so that even Capacitive Sensors Air chambers into polydimethylsiloxane 0.01-0.03 kPa 0.82 kPa −1 31.2 ms >10 000 [111] All-fibrous multilayer nanostructure 0-135 kPa 0.32 V kPa −1 20 s >10 000 [74] Ionic liquid _ 8.21 kPa −1 8000 [112] MXene/P(VDF-TrFE-CFE) 0.04 to 88.89 kPa 16.0 kPa −1 229 ms ≈1500 [119] PSeD-U <2 kPa 2-10 kPa 0.16 kPa −1 0.03 kPa −1 _ 1000 [164] PVDF/NMP, micro-structured PDMS electrode 0-130 Pa 30.2 kPa −1 at 0.7 Pa 25 s 100 000 [113] Deformable ionic mechanotransducer array _ 2.65 nF kPa −1 47 ms 200 [121] LMs@PDMS 3.87% 0.46 kPa −1 _ _ [120] CB/PDMS 0-0.2 kPa 0.2-1.5 kPa 35 kPa −1 6.6 kPa −1 _ 100 [123] Ag NW/flower/Ag NW 0.6 Pa to 115 kPa 1.54 kPa −1 _ 5000 [165] Piezoresistive sensors MXene@fabric-based Up to 150 kPa 6.31 kPa −1 300 ms 2000 [166] Vertical graphene arrays 2.5 Pa to 1.1 MPa 2.14 kPa − 1 6.7 ms 2000 [138] Zinc oxide nanorod 0-100 kPa 0.095 kPa − 1 140 ms _ [144] Thermoplastic polyurethane/polypyrrole/polydopamine/space fabric 0-10 kPa 97.28 kPa −1 60 ms >500 [167] 3D poly(3,4-ethylenedioxythiophene) coated wrinkled nanofiber film 0-3 kPa 397.54 kPa −1 80 ms 16 500 [168] Graphene oxide self-wrapped Copper nanowire networks 0.1-15 kPa 0.144 kPa −1 150 ms 1000 [169] CNTs-UPy/PUa THF 0-6.1 kPa 8.7 kPa −1 40 ms 10 000 [93] Polyacrylonitrile, cellulose, and MXene 0-50 kPa 179.1 kPa −1 _ 10 000 [136] Carbon black/polyaniline nanoparticles/thermoplastic polyurethane fil 0-680% 0.03% 80 ms 10 000 [47] Serpentine Ti/Au metal traces 1-25 kPa 3.78 kPa −1 200 ms 10 000 [67] MXene nanosheets and Fe 3 O 4 nanoparticles 0-2.5 kPa 5.53 kPa −1 62.2 ms 2500 [41] Poly(vinyl alcohol)/poly(vinylidene fluoride) nanofibers spider web structure 0-135 kPa 0.48 V kPa −1 16 s _ [170] Silicon rubber thin film after Ag NW deposition and PEDOT:PSS coating 0-2 kPa 138.0 kPa −1 128 ms _ [140] Hair-epidermis-dermis aerogel electrode 100 Pa to 30 kPa 137.7 kPa −1 80 ms 10 000 [171] Cellulose/carbon nanotube fiber 0-400 kPa 9.364 kPa −1 <2 ms 10 000…”

Emerging Nanomaterials in Healthcare

“…Yao and co-workers employed a facile approach to fabricate graphene arrays on a latex film to develop an eskin. Their research exploited not only morphological properties, but electronic and optical properties of nanomaterials used to fabricate a highly flexible e-skin with multifunctional sensing abilities comparable to those found on human skin [62]. In other studies [63,64], piezoresistive sensors exhibiting high-sensitivity were fabricated and embedded in a prosthetics and intelligent robotics.…”

2D-Materials-Based Wearable Biosensor Systems

“…Hence, the fundamental function of an e-skin is to mimic this pressure sensitivity. To achieve this, various methods are exploited to fabricate e-skin with different modes, including resistive [ 85 ], capacitive [ 86 ], optical [ 87 ], and piezoelectric methods [ 88 , 89 ]. Table 2 summarizes the performance of these four types of e-skin.…”

“…The e-skin is endowed with contactless temperature-sensing capability by the excellent light and thermal sensing properties of graphene. Moreover, the other properties, e.g., ultrafast responsiveness (6.7 ms) and resilience (13.4 ms), a broad pressure sensing range (2.5 Pa–1.1 MPa), a high sensitivity (2.14 kPa −1 ), and robust cyclability (2000), make the e-skin more similar to human skin [ 85 ].…”