wearable sweat sensor

2. Summary of graphene material-based tactile sensors
Nano-Micro Lett.

3. Performance yield of photodetectors based on different 2D materials
May 2022 | Volume 10 | Article

4. technique
• Inkjet printing is among the most actively researched techniques for manufacturing flexible
electronics
• The facile application of novel 2D nanomaterial-based ink formulations has enabled the quick
prototyping of devices across a wide range of fast-growing fields, including motion/tactile
sensing,[22] supercapacitors,[23,24] heat generation,[25–27] strain/ pressure sensors,[28,29]
thermoelectric generators,[30,31] and EMI shielding.
Adv. Funct. Mater. 2022, 32, 2204772

5. challenge
• material synthesis and device fabrication
• the contact resistance at the interface may limit the device performance.
• TMD devices’ FLexibility and stretchability are urgent
• e most frequently used TMDs for current exible electronics and batteries are Mo- and W-based
materials. And for exible biosensors, the material selection is even more limited, as TMDs beyond
MoS2 have barely been applied to such applications. Other TMDs such as XS2 (X ¼ Ni, Pd, Pt)
have comparable band structures to Mo- and W-based TMDs, and exhibit semiconducting/metallic
transfer upon external stress. Hence, they are excellent candidates for exible photoelectric or
electronic devices.304 PtS2 and WSe2 exhibit superior photoelectrochemical performances and are
feasible for photoelectric devices,305 while PtX2 (X ¼ S, Se, Te) may become promising
thermoelectric materials as they present an outstanding calculated ZT over 2 at room
temperature.306 However, these materials have attracted much less attention than MoS2.
Therefore, it is of great potential to explore new TMD materials for different exible devices

6. challenges for fibers/textiles-based flexible sweat sensors,
• the current detection and utilization of components in sweat mainly focus on glucose, lactic acid, urea,
and some ions. However, there are very few reports about the monitoring and utilizing of components
such as proteins, trace elements, and minerals in sweat. Therefore, creating new fibers/ textiles-based
reaction platforms is one of the development directions to expand the analysis of sweat ingredients
ACS Materials Lett. 2023, 5, 1420-1440

7. challenges in the ways LM is used
• its hydrophobicity with most polymeric materials, the difficulties in defining the desired pattern, and
the need to be packaged
• adherence difficulties to polymeric materials
Applied Physics A (2018)

8. Materials 2022, 15, 8731

9. fiber/textiles-based sweat sensors
• do not require additional fixation and have good air permeability
• A fiber is generally a core-sheath structure
• does not require a complicated microchannel structure
• more compact structure and low cost.
• comfortable wearing, scalability, excellent service life, and easy maintainability.
ACS Materials Lett. 2023, 5, 1420-
1440

10. Requirement
material must facilitate sensing, while also
possessing a range of other features, which may
include flexibility, toughness, processability,
biodegradability, and transparency.
ACS Sens. 2023, 8, 1368-
1370
Highly stretchable substrate materials for the realization of head-band integrated potentiometric
sensors for sweat monitoring were reported by Xu and co-workers, demonstrating minimal signal change
upon stretching the device 200%.20 Interestingly, Bae and colleagues recently introduced a simple method
for making stretchable optical waveguides from elastomers. These form the basis of wearable optical sensors
(integrating LEDs, heaters, and photodetectors) and have been successfully used to monitor heart rate,
breathing, and blood oxygen saturation.21 Due to its low cost and availability, paper is particularly interesting
for single use colorimetric applications, where test outcome can be read by eye or a smartphone