Washable and flexible screen printed graphene electrode on textiles for wearable healthcare monitoring

Abstract

Electrocardiogram (ECG) is an essential route to monitor and prevent cardiovascular related disease. Conventional silver/silver chloride (Ag/AgCl) electrodes are not able to be used for long-term monitoring due to the drying of gel and skin irritation. Graphene has been investigated as a promising material for wearable health-monitoring electronics. Here, a graphene-coated textile electrode was developed for ECG monitoring. The graphene electrode was prepared by screen printing graphene ink on a pre-modified textile substrate. The electrical resistance of the graphene textile electrode can be controlled by increasing the printing passes. The ECG signals obtained by the graphene textile electrode showed comparable performance to the conventional Ag/AgCl electrode. The graphene textile electrode shows satisfactory washability, high flexibility and good tortuosity. The performance of the ECG signal shows negligible change over nine washing cycles and 2000 bending cycles. Overall, the screen-printed graphene textile electrode in this work presents an inexpensive fabrication platform solution for long-term healthcare monitoring in wearable electronics.

6.2: Invited Paper: Wearable and Printable Sensors for Human Healthcare Monitoring

“…[1] Here, we proposed two kinds of sensors for wearable healthcare monitoring. [2][3][4] Firstly, we developed a highly stretchable and printable polymer composite by adding small amount of silver nanowires in stretchable conductive polymer materials, which shows excellent stretchability up to 500%. The stretchable strain sensor based on the polymer/AgNWs composite can respond to strain signals in real time, even for 1% strain response, and shows excellent stability over 1000 loading/unloading cycles.…”

Bioinspired Temperature‐Sensitive Yarn with Highly Stretchable Capability for Healthcare Applications

“…Attributed to inherent characteristics of fiber materials or fiber assemblies such as softness, biocompatibility, large deformation, as well as permeability, significant advances have been made toward the realization of fiber‐based wearable electronic devices, [ 1 ] including skin‐like electrodes, circuits or transistors, nanogenerators or supercapacitors and most importantly the sensors, which bring forward novel fabrication technologies [ 2,3 ] as well as practical applications in diverse fields, [ 4,5 ] such as electronic skins, [ 6,7 ] sophisticated soft robotics, [ 8 ] human–machine interaction, [ 9 ] as well as healthcare monitors or biomedical rehabilitation. [ 10,11 ]…”

Encapsulation of Electrically Conductive Apparel Fabrics: Effects on Performance

“…A number of papers include treating fabrics with graphene (reduced graphene oxide [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], graphene nanoplatelets [ 23 , 24 , 25 , 26 , 27 , 28 ], nanoribbon [ 29 ], multilayer graphene [ 30 ], graphene [ 18 , 31 , 32 , 33 ]). These report electrical resistance, surface characteristics (SEM, TEM), and surface chemistry (FTIR, Raman) for example.…”

“…Conferring electrical conductivity has been successful and performance as a sensor (e.g., to strain) has been demonstrated; however, challenges related to stability and durability for the end use typically remain. Change with wash [ 15 , 16 , 19 , 22 , 23 , 24 , 28 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] and with abrasion [ 7 , 16 , 34 , 35 , 43 , 44 ] have received some attention, but change with storage has not been well identified. There is little clarity and consistency in how and the extent to which properties critical to most wear-related applications change: Permeability to air [ 16 , 31 , 45 , 46 , 47 ], permeability to water vapor [ 16 , 46 , 47 ], moisture regain [ 46 , 48 ], thermal resistance [ 24 , 31 , 49 ], contact angle [ 8 , 15 , 28 , 31 , 33 , 50 , 51 , 52 , 53 ].…”

“…In the case of fabrics, reporting resistance relative to dimensions is preferable due to diverse specimen sizes which are functionalized. Ohm/square [ 27 , 28 , 56 , 57 , 58 , 59 , 60 , 61 ] or ohm/meter [ 30 , 57 , 61 , 62 , 63 , 64 , 65 ] are common in the scientific literature, the latter sometimes converted to Siemens/meter [ 22 , 66 , 67 , 68 , 69 ]. The Van de Pauw method [ 70 ] has been used to measure specific surface resistivity of fabrics mostly based on four-point probe measurements, especially when irregular material shapes are examined [ 56 , 71 ].…”