Abstract
This paper presents a theoretical model for a human skin-wearable annular thermoelectric generator (WATEG) system and provides analytical solutions for its energy conversion performance. The Pennes equation is used to model the heat transfer of human skin, which is assumed to be a cylindrical multilayer structure composed of subcutis, dermis, and epidermis. The heat exchanges induced by blood perfusion and metabolic heat generation within the skin tissue are taken into account. It is found that the influence of skin effect and contact thermal resistance between the human skin and flexible substrate plays a significant role in the energy conversion performance of the WATEG and should be considered. The matched load resistance, optimal fill factor, and height of thermoelectric legs are determined through numerical analysis. The findings of this study can be applied to the practical design of WATEG devices and are expected to contribute to their optimization.
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Abbreviations
- A :
-
Area (m2)
- c :
-
Specific heat (J/kg/K)
- F :
-
Fill factor (%)
- H :
-
Height (m) or microhardness (MPa)
- h :
-
Convection coefficient or contact thermal conductance (W/m2/K)
- I :
-
Current (A)
- j :
-
Current density (A/m2)
- K :
-
Thermal conductance (W/K)
- P :
-
Power output (μW/cm2) or contact pressure (kPa)
- Q :
-
Heat flux (W)
- q :
-
Heat flux density (W/m2)
- R :
-
Electric resistance (Ω)
- r :
-
Radius (mm)
- T :
-
Temperature (K)
- α :
-
Seebeck coefficient (V/K)
- Δa :
-
Asperity slope (rad)
- \(\delta \) :
-
Thicknesses (mm)
- \(\theta \) :
-
Angle (rad)
- ε :
-
Surface roughness (μm)
- ρ :
-
Density (kg/m3)
- σ :
-
Electric conductivity (S/m)
- λ :
-
Thermal conductivity (W/m/K)
- ω :
-
Blood perfusion rate (mL/mL/s)
- a:
-
Ambient environment
- b:
-
Blood
- c:
-
Contact interface
- d:
-
Dermis
- e:
-
Epidermis
- eff:
-
Effective property
- en:
-
Encapsulation layer
- f:
-
Convection at heat sink
- fm:
-
Fill material
- i:
-
i-th layer
- m:
-
Metabolism
- n:
-
N-type thermoelectric leg
- out:
-
Output
- p:
-
P-type thermoelectric leg
- s:
-
Body core temperature or subcutis
- DPL:
-
Dual-phase-lag
- TEG:
-
Thermoelectric generator
- WATEG:
-
Wearable annular thermoelectric generator
- WTEG:
-
Wearable thermoelectric generator
References
X. Wang, Z. Liu, and T. Zhang, Flexible sensing electronics for wearable/attachable health monitoring. Small 13(25), 1602790 (2017).
T.Q. Trung and N.-E. Lee, Flexible and stretchable physical sensor integrated platforms for wearable human-activity monitoring and personal healthcare. Adv. Mater. 28(22), 4338–4372 (2016).
A.S. Dahiya, J. Thireau, J. Boudaden, S. Lal, U. Gulzar, Y. Zhang, T. Gil, N. Azemard, P. Ramm, T. Kiessling, C. O’Murchu, F. Sebelius, J. Tilly, C. Glynn, S. Geary, C. O’Dwyer, K.M. Razeeb, A. Lacampagne, B. Charlot, and A. Todri-Sanial, Review-energy autonomous wearable sensors for smart healthcare: a review. J. Electrochem. Soc. 167(3), 037516 (2019).
W. Ren, Y. Sun, D. Zhao, A. Aili, S. Zhang, C. Shi, J. Zhang, H. Geng, J. Zhang, L. Zhang, J. Xiao, and R. Yang, High-performance wearable thermoelectric generator with self-healing, recycling, and Lego-like reconfiguring capabilities. Sci. Adv. 7(7), eabe0586 (2021).
A. Nozariasbmarz, H. Collins, K. Dsouza, M.H. Polash, M. Hosseini, M. Hyland, J. Liu, A. Malhotra, F.M. Ortiz, F. Mohaddes, V.P. Ramesh, Y. Sargolzaeiaval, N. Snouwaert, M.C. Özturk, and D. Vashaee, Review of wearable thermoelectric energy harvesting: from body temperature to electronic systems. Appl. Energy 258, 114069 (2020).
P. Kolarsick, M.A. Kolarsick, and C. Goodwin, Anatomy and Physiology of the Skin. J. Dermatol. Nurs. Assoc. 3(4), 203 (2011).
N. Djongyang, R. Tchinda, and D. Njomo, Thermal comfort: a review paper. Renew. Sust. Energy. Rev. 14(9), 2626–2640 (2010).
G. Kelly, Body temperature variability (Part 1): a review of the history of body temperature and its variability due to site selection, biological rhythms, fitness, and aging. Altern. Med. Rev. 11(4), 278 (2006).
F. Suarez, A. Nozariasbmarz, D. Vashaee, and M.C. Öztürk, Designing thermoelectric generators for self-powered wearable electronics. Energy Environ. Sci. 9, 2099–2113 (2016).
D. Wijethunge, D. Kim, and W. Kim, Simplified human thermoregulatory model for designing wearable thermoelectric devices. J. Phys. D Appl. Phys. 51, 055401 (2018).
A.B. Zhang, G.Y. Li, B.L. Wang, and J. Wang, A theoretical model for wearable thermoelectric generators considering the effect of human skin. J. Electron. Mater. 50, 1514–1526 (2021).
A.B. Zhang, D.D. Pang, B.L. Wang, and J. Wang, Dynamic responses of wearable thermoelectric generators used for skin waste heat harvesting. Energy 262, 125621 (2023).
F. Suarez, D.P. Parekh, C. Ladd, D. Vashaee, M.D. Dickey, and M.C. Öztürk, Flexible thermoelectric generator using bulk legs and liquid metal interconnects for wearable electronics. Appl. Energy 202, 736–745 (2017).
M.H. Jeong, K.C. Kim, J.S. Kim, and K.J. Choi, Operation of wearable thermoelectric generators using dual sources of heat and light. Adv. Sci. 9(12), 2104915 (2022).
Z.G. Shen, S.Y. Wu, and L. Xiao, Theoretical analysis on the performance of annular thermoelectric couple. Energy Convers. Manag. 89, 244–250 (2015).
S.C. Kaushik and S. Manikandan, The influence of Thomson effect in the energy and exergy efficiency of an annular thermoelectric generator. Energy Convers. Manag. 103, 200–207 (2015).
A.B. Zhang, B.L. Wang, D.D. Pang, L.W. He, J. Lou, J. Wang, and J.K. Du, Effects of interface layers on the performance of annular thermoelectric generators. Energy 147, 612–620 (2018).
A.B. Zhang, B.L. Wang, D.D. Pang, J.B. Chen, J. Wang, and J.K. Du, Influence of leg geometry configuration and contact resistance on the performance of annular thermoelectric generators. Energy Convers. Manag. 166, 337–342 (2018).
Z.F. Wen, Y. Sun, A.B. Zhang, B.L. Wang, J. Wang, and J.K. Du, Performance analysis of a segmented annular thermoelectric generator. J. Electron. Mater. 49, 4830–4842 (2020).
S.F. Fan and Y.W. Gao, Numerical analysis on the segmented annular thermoelectric generator for waste heat recovery. Energy 183, 35–47 (2019).
H.H. Pennes, Analysis of tissue and arterial blood temperatures in the resting human forearm. J. Appl. Physiol. 1, 93–122 (1948).
M. Bahrami, J.R. Culham, and M.M. Yovanavich, Modeling thermal contact resistance: a scale analysis approach. J. Heat Transf. 126, 896–905 (2004).
F. Xu, T.J. Lu, and K.A. Seffen, Biothermomechanics of skin tissues. J. Mech. Phys. Solids 56, 1852–1884 (2008).
Y.C. Wang, Y.G. Shi, D.Q. Mei, and Z.C. Chen, Wearable thermoelectric generator for harvesting heat on the curved human wrist. Appl. Energy 205, 710–719 (2017).
H.N. Ho and L.A. Jones, Modeling the thermal responses of the skin surface during hand-object interactions. J. Biomech. Eng. T ASME 130, 021005 (2008).
F.P. Incropera, D.P. DeWitt, T.L. Bergman, and A.S. Lavine, Fundamentals of Heat and Mass Transfer, 6th ed., (New York: Wiley, 1996).
M. Gao, New formulation of the theory of thermoelectric generators operating under constant heat flux. Energ. Environ. Sci. 15, 356–367 (2022).
A.B. Zhang, J. Lou, B.L. Wang, and J. Wang, A Griffith crack model in a generalized nonhomogeneous interlayer of bonded dissimilar half-planes. J. Theort. Appl. Mech. 61, 495–507 (2023).
A.B. Zhang and B.L. Wang, Temperature and electric potential fields of an interface crack in a layered thermoelectric or metal/thermoelectric material. Int. J. Therm. Sci. 104, 396–403 (2016).
Acknowledgments
The research was supported by the Natural Science Foundation of Zhejiang Province of China (LY21A020004), the Natural Science Foundation of Ningbo (2022J095), the Natural Science Youth Foundation of Henan Province (232300420336), the Key University Scientific Research Project of Henan Province (22A610007), and the Special Scientific Research Fund Project of Cultivating Master Graduates of Huangshan University (hsxyssd008).
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Appendices
Appendix A
The constants \({B}_{i}\) and \({D}_{i}\) (\(i=s, d\) and \(e\)):
where \(K_{s} = \frac{{\lambda_{s} \theta \delta }}{{{\text{ln}}\left( {r_{d} /r_{s} } \right)}}, K_{d} = \frac{{\lambda_{d} \theta \delta }}{{{\text{ln}}\left( {r_{e} /r_{d} } \right)}}, K_{e} = \frac{{\lambda_{e} \theta \delta }}{{{\text{ln}}\left( {r_{c} /r_{e} } \right)}}\) are the thermal conductances of subcutis, dermis, and epidermis, respectively.
Appendix B
The temperatures \(T_{d}\), \(T_{e}\) and \(T_{c}\), and the constants \(\gamma_{1}\), \(\gamma_{2}\), \(\Omega_{c}\) and \(\Omega_{s}\):
with
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Guo, C., Zhang, A., Pang, D. et al. Energy Conversion Performance and Optimization of Wearable Annular Thermoelectric Generators. J. Electron. Mater. 52, 7325–7336 (2023). https://doi.org/10.1007/s11664-023-10636-y
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DOI: https://doi.org/10.1007/s11664-023-10636-y