Fully printed and flexible carbon nanotube-based thermoelectric generator capable for high-temperature applications

Recent Advances in Materials for Wearable Thermoelectric Generators and Biosensing Devices

“…Figure 2 shows the advancement in the design and soft packaging of WTEG for flexibility and stretchability [15,18,21,[24][25][26]. It indicates considerable improvements in the thermoelectric performance of flexible TEGs [18,19,22,23].…”

“…It is noteworthy that soft packaging improved the strain tolerance from 3% to 20% for inorganic thermoelectric material-based flexible TEGs, which successfully generated thermoelectric power from ~693.5 nW (13 np pairs, ∆T = 24 K) to ~7.02 mW (220 np pairs, ∆T = 40 K) [15,21]. Al-though organic material-based TEG devices successfully generated ~39 µW (336 np pairs, ∆T = 50 K), however, these could only generate 2.6 µW at ∆T = 6 K for wearable applications, which is sufficient to power a low-power biosensor with a good strain tolerance [24]. Another parameter, magnetothermopower, to improve the thermoelectric performance of TEGs has been introduced.…”

“…However, this review only focuses on nonmagnetic semiconducting materials. material-based TEG devices successfully generated ~39 µW (336 np pairs, ΔT = 50 K) however, these could only generate 2.6 µW at ΔT = 6 K for wearable applications, which is sufficient to power a low-power biosensor with a good strain tolerance [24]. Another parameter, magnetothermopower, to improve the thermoelectric performance of TEGs has been introduced.…”

“…A typical fabrication process for a WTEG includes four simple steps: 1-fabrication of bottom and top electrodes; 2-fabrication of p-and n-type legs; 3-placement of n-and p-type legs over electrodes and soldering them; and 4-soft packaging of the WTEG. It exhibits the advantage of converting human body heat into electrical energy at very low-temperature differences, i.e., ∆T = ~3 K, by using the Seebeck effect of thermoelectric material and generates electrical energy from a few nW to several mW [19,22,24,35] (Figure 3A). It is advantageous because the human thermoregulatory system continuously regulates the human body temperature to 37 • C (Figure 3B).…”

Sensors-on-paper: Fabrication of graphite thermal sensor arrays on cellulose paper for large area temperature mapping

“…Further, the existing thermoelectric energy conversion devices/generators are usually manufactured from toxic and expensive semiconductors such as bismuth tellurides, led tellurides, and their alloys [26] , [27] , [28] . Therefore, the current thermoelectric research is focused on finding low-cost and non-toxic thermoelectric conductors for the application [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] . With some improvements and modifications in the thermoelectric properties of graphite such as by organic doping or alloying with other semiconductors, they can also be utilized in the fabrication of thermoelectric devices [19] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] .…”