Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | School of Fashion and Textiles | en_US |
| dc.contributor.advisor | Zheng, Zijian (SFT) | en_US |
| dc.creator | Zhang, Pengxiang | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/14516 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Thermo-e-skin : functional bionic engineering to achieve thermoregulation and thermosensation | en_US |
| dcterms.abstract | Electronic skin (e-skin) has broad application scenarios, including wearable technology, human-computer interfaces, smart prosthetics, and medical diagnosis, due to its ability to mimic human skin and offer versatile sensing capabilities. However, the state-of-art thermosensation is insufficient for comprehensive environmental perception. Furthermore, traditional e-skins cannot regulate temperature, like the human body with the isothermal function. This thesis conducts a systematic investigation of thermo-e-skin with both thermoregulation and thermosensation functions. | en_US |
| dcterms.abstract | Two types of thermoregulation have been proposed, i.e. single-mode thermoregulation e-skin (S-thermo-e-skin) and dual-mode thermoregulation e-skin (D-thermo-e-skin). The S-thermo-e-skin involved a flexible thermoelectric device and a heat sink made of a phase change material, enabling the e-skin to maintain the isothermal function in both hot and chilly environments. The S-thermo-e-skin has a good isothermal function, maintaining a surface temperature of 35 °C in a broad environment with a temperature range of 10-45 °C. The effective time in the isothermal state of 35 °C could be over 2 hours in the mild environment with 10-30 °C, while decreased to 1.5 h and 0.75 h under the ambient temperature of 40 and 45 °C, respectively. The energy cost to maintain the isothermal state is a careful measurement, showing the lowest value of 14.22 mW/cm² within the thermoneutral zone of 35 °C. Furthermore, the D-thermo-e-skin is functionalized with the active mode of flexible thermoelectric thermoregulation layers and the passive mode of ionic hydrogel's evaporation/regeneration layer. The ionic hydrogel mimics the function of the bionic sweat gland. The D-thermo-e-skin significantly increased the effective time of 35 °C-isothermal-state, e.g. increased from 2h to 4.2 h under ambient temperature 40 °C. Furthermore, the e-skin's hygroscopic properties allowed it to return to its initial state within 4 hours when exposed to 90% humidity, enabling reusability. Both the S-thermo-e-skin and D-thermo-e-skin have a quick response as the e-skin as the environment changes. | en_US |
| dcterms.abstract | A new heat-source-identification sensor was designed by using the capacitance response behavior of the methoxy poly (ethylene glycol) acrylate ionic gel. The ionic-gel sensor exhibits an impressive ultra-wide temperature range of -20 °C to 180 °C and displays a highly linear response to temperature stimuli (R² = 0.993), and a temperature measurement accuracy of better than 0.005 °C. Moreover, the ionic-gel sensor has temperature-sensitive ion relaxation time and pressure-sensitive capacitance, which provides an effective to decouple the temperature and pressure signals. Furthermore, the ionic-gel sensor also shows proximity sense with a negative capacitance response. It was experimentally verified that the ionic sensor could identify the heat exchange modes, encompassing thermal radiation, thermal convection, and thermal conduction, by using the ion relaxation time and capacitance response. The heat-source-identification well mimics the thermosensation of human skin. Moreover, the integration of thermoregulation and thermosensation was conducted. The integrated thermo-e-skin successfully combines thermosensation, heat-source-identification, signal feedback, and thermoregulation, demonstrating a bionic thermo-sensory capability. This thesis provides a systematic solution to mimic the thermoregulation and thermosensation of human skin, which would has significant impact on the field of thermo-e-skin. | en_US |
| dcterms.extent | xxii, 160 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2024 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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