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Page 24 of 34 Xi et al. Soft Sci 2023;3:26 https://dx.doi.org/10.20517/ss.2023.13

Challenges and outlook
Wearable self-powered sensors have made great progress. It has great advantages in convenience and
comfort, real-time monitoring, and material reuse. The self-power effect achieved by TENGs, PENGs, and
other technologies also plays an important role in medical care, sports, fitness, and environmental
[48]
monitoring . Wearable self-powered sensors can be used everywhere in the human body, including smart
etc.
watches, ECG and heart rate monitoring, temperature sensors, respiratory sensors, [21,24] . Due to their
wide range of applications, self-powered wearable sensors can play an important role in the IoT. Self-
powered wearable sensors can provide a lot of real-time and long-term data for the IoT and realize a more
interconnected and data-driven system. With the continuous progress of technology, self-powered wearable
sensors and the IoT are expected to continue to develop, bringing innovation and progress. However, the
self-powered wearable sensor still has some problems .
[164]
Self-powered wearable sensors produce insufficient energy. These sensors generate energy through the
movement of a wearer or the surrounding environment. Their output performance is often not enough to
support all the required electrical equipment. Or the power supply requires a large range of human
movement, which limits its use in various environments. Unreliable power supply conditions pose a great
challenge to the use of sensors. This will also lead to some other problems. The sensing range of self-
powered wearable sensors is often limited due to low power supply. This will result in reduced accuracy and
sensitivity. Due to the limited power supply, the self-powered wearable sensor may not be able to transmit
data continuously. This may result in delayed or incomplete data transmission, resulting in information loss
or incomplete analysis. Due to the low power supply, the response time of the self-powered wearable sensor
may be longer. This will delay the detection of changes in physiological or environmental parameters, thus
reducing the effectiveness of the sensor. Due to the natural degradation of the materials used in the sensor
or the limited capacity of the energy storage device, the life of the self-powered wearable sensor may be
limited. Although some sensors have high stability and long service life, their unstable output performance
may cause the service life of other devices to decline. The power shortage of self-powered wearable sensors
is a major challenge that needs to be solved through the progress of technology and materials science. To
solve this problem, there are several methods that can be used. First, add energy storage devices, such as
capacitors or batteries, to increase the energy reserve of the sensor, thereby increasing the working time and
stability of the sensor. Second, the energy management system of the sensor can be optimized to maximize
the use of harvested energy. For example, more efficient energy conversion devices, optimized energy
storage, distribution algorithms, , can be adopted. In addition, technologies such as sensors and
etc.
processors with low power consumption can be used to reduce the energy consumption of the sensor,
thereby prolonging the working time of the sensor. At the same time, multiple energy sources can be used
for joint energy supply, such as solar energy, thermal energy, vibration energy, , and they can be
etc.
integrated to achieve a more reliable energy supply. Finally, managing the operating mode of the sensor is
also an effective way to solve the energy shortage problem. The working mode of the sensor can be
reasonably adjusted according to needs to avoid energy waste and improve energy utilization. For example,
the sensor is only turned on when it needs to be monitored to avoid unnecessary work for a long time. To
sum up, in order to solve the problem of insufficient energy generated by self-powered wearable sensors,
various methods can be adopted, such as adding energy storage devices, optimizing energy management
systems, adopting low-power consumption technologies, using other energy sources in combination, and
managing the working modes of sensors.

Another challenge for self-powered wearable sensors is low durability, which will limit the life and reliability
of the sensor. Wearable sensors are exposed to various environmental conditions, such as temperature
changes, humidity, mechanical stress, and chemical corrosion, which will cause damage to the sensor over
time. Material degradation is common to many self-powered sensors composed of polymer materials, which
may lead to sensor misalignment or failure. Repeated mechanical stress may also cause damage to the
sensor, resulting in sensor failure. The sensor that often works in sweat or wet exhaled gas may fail due to