Page 114 - Read Online

Xi et al. Soft Sci 2023;3:26 https://dx.doi.org/10.20517/ss.2023.13 Page 23 of 34

Fabric
Wearable self-powered sensors can be integrated into fabrics to create smart textiles that can monitor all
[38]
aspects of human physiology and activities . Compared with traditional rigid sensors, fabric-based sensors
[49]
have many advantages, including being more comfortable, flexible, and easier to use . Sensors based on
self-powered fabrics can be used to monitor various physiological parameters, such as heart rate,
[215]
respiration, and muscle activity . They can also be used to track movement, postures, and environmental
factors such as temperature and humidity . The energy generated by the sensor can be used to power the
[216]
[217]
sensor itself or charge the battery for later use . As shown in Figure 8F, Li et al. proposed a self-
luminescent and energy-collecting triboelectric fiber as a wearable energy supplier, self-powered sensor, and
human-machine interface. It includes a conductive wire wrapped in an elastic phosphorescent triboelectric
composite, which can be woven into a large-area high-tensile fabric for sustainable power supply. It can
convert biomechanical energy into usable electrical energy. It is developed as system-level smart clothing
using newly designed optical fiber. As shown in Figure 8G, Zhou designed a waterproof and breathable
fabric TENG (CSYF TENG) based on nano/micro-core sheath yarn and used it for energy collection and
[218]
self-powered humidity and subtle force sensing . Unlike coated yarn, nanofibers are tightly and orderly
wrapped around conductive fibers through conjugated electrospinning technology. CSYF TENGs exhibit
superior electrical output, excellent durability, and biomechanical pressure sensitivity and become ideal self-
powered humidity sensors. The TENG can also be used as a bioenergy harvester, a self-powered micro-force
sensor, and a fabric-based electronic skin.

Integrated clothing
Integrated wearable self-powered clothing sensors represent a type of intelligent clothing that combines self-
powered sensors to monitor all aspects of human physiology and activities [175,219] . By integrating these
sensors into clothing, they offer more powerful functions and improved convenience [220] . As shown in
Figure 8H, He et al. developed an ultra-light self-powered fire alarm (SFA) electronic textile based on
electrical conductive gel fiber, which includes calcium alginate (CA), Fe O nanoparticles (Fe O NP), and
3
4
3
4
silver nanowires (Ag NW), realizing ultra-sensitive temperature monitoring and energy collection in fire
[175]
suits . The resulting SFA electronic fire extinguisher is integrated into the fire protection clothing to
achieve temperature sensing and repeatable fire alarm functions. In addition, based on SFA electronic fire
extinguisher, an automatic fire self-rescue positioning system is further established. Designing wearable self-
powered clothing sensors is a comprehensive endeavor that requires consideration of multiple factors. First,
the required sensor type, functionality, accuracy, and sensitivity requirements and how they fit together to
achieve the desired functionality need to be determined. Secondly, soft, breathable, and comfortable
materials suitable for human skin need to be selected, and aspects such as reliability, durability,
environmental protection, and cost must be considered. Then, it is necessary to design an energy supply
scheme that can meet the energy demand of the sensor, such as solar energy, kinetic energy, chemical
energy, , and ensure that sufficient energy supply can be maintained during use. In addition, it is also
etc.
necessary to consider how to design data processing and transmission schemes to transmit data collected by
sensors to devices or the cloud for processing and analysis while ensuring data security and privacy. At the
same time, ergonomic design also needs to be considered to ensure that the sensor does not cause
discomfort to the human body or affect its performance when worn. Interaction design is also an important
aspect. It is necessary to consider how to design the way users interact with sensors to improve user
experience and usage efficiency. Finally, the manufacturability and cost of the product also need to be
considered to ensure that the product can be widely used in the market and remain competitive. Therefore,
designing wearable self-powered clothing sensors requires comprehensive trade-offs and designs to meet
the needs and requirements of multiple aspects.