Smart Glove Integrated with Tunable MWNTs/PDMS Fibers Made of a One-Step Extrusion Method for Finger Dexterity, Gesture, and Temperature Recognition

Abstract

Flexible wearable devices have proven to be emerging tools for motion monitoring, personal healthcare, and rehabilitation training. The development of a multifunctional, flexible sensor and the integration of sensors and a smart chip for signal reading and transmission play a critical role in building a smart wearable device. In this work, a smart glove based on multiwalled carbon nanotubes/poly­(dimethylsiloxane) (MWNTs/PDMS) fibers is developed for gesture and temperature recognition. First, the well-tunable, stretchable, and thermal-sensitive MWNTs/PDMS fibers are fabricated via a facile and cost-effective one-step extrusion method. The obtained fibers exhibit an outstanding linear relationship between resistance change and strain in the range of 0–120% and excellent cyclic stability and durability after 20 000 cycles of 50% tension. They also present a linear relationship of resistance change and temperature of 0.55% °C–1 with a correlation coefficient of 0.998 in the range of 0–100 °C. The fibers, as parts of wearable sensors, are then integrated into a smart glove along with a custom-made data acquisition chip to recognize finger dexterity, gestures, and temperature signals and output them through a screen display, an audio system, and Bluetooth transmission. The highly integrated, low-cost, and multifunctional glove holds great potential for various applications, such as sign language recognition, rehabilitation training, and telemedicine in the Internet-of-Things era.

Flexible and stretchable polymer optical fibers for chronic brain and vagus nerve optogenetic stimulations in free-behaving animals

“…The strain at break of the POFs is higher than 150%, implying a superior stretchability compared to the reported polymer-based optical implants for in vivo optogenetics [29,36]. In addition, we did not observe noticeable cracks or significant influence on the output power of the POFs after repeated 100% stretching deformation, which implies an excellent mechanical stability of the fabricated optical waveguides [37][38][39]. Those advantages greatly expand the potential applications of optogenetics and enable optical delivery in soft tissues even with large deformations.…”

Textile-Based Mechanical Sensors: A Review

“…The structure of composite fibers is more integrated than that of coated textiles, effectively improving the problem of micro-cracks on the surface of coated fibers. Li et al [36] used a syringe to extrude a mixture of conductive multiwalled carbon nanotubes (MWCNTs) and PDMS through a mesh with micron-sized holes to fabricate functional fibers (Figure 1b). The fibers as part of a wearable sensor were then integrated into a smart glove to recognize finger dexterity, gestures, and temperature signals.…”

“…Capacitive TMSs feature properties of high response repeatability, small signal drift, long term cycle stability, and low energy consumption, but they are susceptible to external field interference, relatively low sensitivity, and limited sensing range [44]. [35]; (b) extrusion, reproduced with permission from [36]; (c) printing, reproduced with permission from [37]; and (d) wet spinning, reproduced with permission from [38]; (e) Yarn-based sensors prepared by electrostatic spinning, reproduced with permission from [39]; Fabric-based sensors prepared by (f) spraying, reproduced with permission from [41]; and (g) screen printing, reproduced with permission from ref. [42].…”

“…The capacitance of a sensing device is defined as C = εrεoA/d, where εr is the relative permittivity, εo is the vacuum permittivity, A is the effective area of the electrode, and d is the pole-plate spacing [43]. Therefore, the change of one or more parameters of the permittivity, spacing, or effective area will cause a change in capacitance of the device, and then the magnitude of the mechanical stimulus [35]; (b) extrusion, reproduced with permission from [36]; (c) printing, reproduced with permission from [37]; and (d) wet spinning, reproduced with permission from [38]; (e) Yarn-based sensors prepared by electrostatic spinning, reproduced with permission from [39]; Fabric-based sensors prepared by (f) spraying, reproduced with permission from [41]; and (g) screen printing, reproduced with permission from ref. [42].…”

“…PDMS means polydimethylsiloxane, MWNTs means multi-walled carbon nanotubes, PEDOT:PSS means poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate), rGO means reduced graphene oxide and AgNWs means silver nanowires. Fiber-based sensors prepared by (a) coating, reproduced with permission from[35]; (b) extrusion, reproduced with permission from[36]; (c) printing, reproduced with permission from[37]; and (d) wet spinning, reproduced with permission from[38]; (e) Yarn-based sensors prepared by electrostatic spinning, reproduced with permission from[39]; Fabric-based sensors prepared by (f) spraying, reproduced with permission from[41]; and (g) screen printing, reproduced with permission from ref [42]…”