Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | School of Fashion and Textiles | en_US |
| dc.contributor.advisor | Tao, Xiaoming (SFT) | en_US |
| dc.contributor.advisor | Zhang, Lisha (SFT) | en_US |
| dc.creator | Yang, Jing | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/13834 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Study of textile-based wearable fluidic fabrics for sports recovery | en_US |
| dcterms.abstract | Rapid contrast therapy (RCT) through water immersion is widely used by athletes for effective sports recovery, involving cyclic transitions between cold (~ 10 °C) and warm (~ 40 °C) water. Despite its benefits, RCT's application is often restricted by high water consumption, bulky equipment, hygiene concerns, and inconvenience at training or competition venues. There is a need for a wearable device to replace traditional water-immersed RCT, focusing on rapid cold/warm transitions, large skin coverage, lightweight and flexible design, and portability. However, current wearable technologies fall short of these requirements. Meanwhile, the heat transfer coefficient of existing liquid cooling devices was estimated to range only from 13 to 37 W/(m²·K) when they are worn on the body, much lower than that achieved when body was immersed in cold water (107 W/(m²·K)). This research investigates wearable fluidic fabrics capable of matching the heat transfer performance of water immersion. The study involves: 1) experimental investigation of various wearable technologies, identifying fluidic fabric as the most viable approach; 2) development of an experimentally validated heat transfer model, pinpointing key influencing factors; and 3) optimization of the fluidic fabric, comparing its heat transfer coefficient to that of traditional water-immersed therapy. | en_US |
| dcterms.abstract | To explore potential approaches for developing wearable devices that meet specific cooling, heating, and transition performance requirements. Two wearable technologies were investigated: thermoelectric (TE) device and tube-based fluidic device. TE device can alternate between cooling and heating by reversing the current direction, although their transition duration requires further exploration. Tube-based fluidic devices, such as liquid cooling garments (LCGs), regulate temperature by circulating coolant to provide both cooling and heating effects through water temperature adjustments. For TE modules equipped with air-cooled heat sink unit, improved heat dissipation and increased input power effectively reduce transition duration between modes. For water-cooled heat sink unit, using a cooler 14 °C coolant decreases the hot-to-cold transition duration (from 48 s to 24 s) but increases the cold-to-hot transition duration (from 24 s to 38 s). Conversely, a tube-based fluidic device has longer transition duration due to the thick walls and low thermal conductivity of silicone tubes, with 92 s for cold-to-hot and 69 s for hot-to-cold transitions. We then propose a third approach: a novel flexible heat transfer panel (FHTP) with textile-based fluidic channels for water circulation. The FHTP eliminates electrical risks and provides a large effective area in comparison to TE modules and tube-based devices. Using an experimental setup capable of supplying both cold and hot water, FHTPs designed for the use of lower limb and thigh can achieve rapid transitions between cold and hot modes in just 15 s. Preliminary evaluations suggest that the thermal insulation fabric enhances heat transfer between the skin and fluidic fabric during a standard RCT. | en_US |
| dcterms.abstract | Simplified analytical models were developed to improve the comprehension of heat transfer process between the FHTP and the skin or surroundings. Unlike traditional models for tube-based LCGs, which often overlook contact conditions, our research incorporates interfacial contact conditions (contact pressure and area ratio) into the equivalent thermal resistance network. This consideration is crucial as the flexible fluidic channel can deform under varying flow rates. Experimental validation shows that when contact pressure and area ratio data are input into the analytical models, the trends of heat transfer rate (Qf) and outlet water temperature (Tout) closely match the experimental results. The experimental values of Qf and Tout fall within the analytical range when assuming the thermal conductivity of the FHTP to be between 0.04 and 0.6 W/(m²·K). To further refine the model, a correction factor, fint, is introduced to adjust the interfacial thermal conductivity between the skin and the FHTP. The margin of error is minimized to below 10 % when fint is set to 0.375. The modified model is further validated with experimental data under varying inlet water temperatures, confirming its reliability. To accurately describe the heat transfer performance of the wearable fluidic fabric, two criteria are further proposed: the heat transfer rate between the wearable fluidic fabric and the skin (Qs) and the effectiveness of the fluidic fabric (η). The derived models for Qs and η allow for the prediction of the influences of various parameters, including the dimensions of the fluidic channel, thermophysical properties of the fabric, water flow conditions, and air temperature, on the heat transfer performance. | en_US |
| dcterms.abstract | An orthogonal design and range analysis to quantitatively identify the main factors influencing the Qs and η of the fluidic fabric. Four factors were selected based on model predictions: Rpi, Rt, Tin and ν. Tin and ν are revealed as the primary and secondary factors affecting both Qs and η, respectively. Rt is crucial for achieving high η, while Rpi ranging from 0.002 to 0.006 m²·K/W has minimal impact on these indices. Following this analysis, a new thigh-worn fluidic fabric was fabricated and measured its skin heat transfer coefficient through human trials. The average coefficient is 98.5 W/(m²·K), achieving 92 % of the coefficient of direct water immersion at 10 °C and significantly outperforming previously reported cooling garments, which are estimated to range from 13 to 37 W/(m²·K). Our fluidic fabric also surpasses a commercial cold therapy wrap in cooling temperature, effectiveness, and heat transfer coefficient. Additionally, the fabric demonstrates reliability and stability, enduring 1000 cycles of cooling/heating (from ~ 5 °C to ~ 40 °C) with intermittent pressurization mode (internal hydraulic pressure up to 50 kPa). | en_US |
| dcterms.abstract | In summary, the wearable fluidic fabric with FHTP as the core layer demonstrates an excellent heat transfer performance that is close to water immersion for sports recovery. This fluidic fabric also holds potentials in diverse applications, such as enhancing thermal safety and comfort in extreme environments (e.g., personal thermal management systems and fire-protection suits), supporting cryotherapy and thermotherapy in rehabilitation and healthcare, and simulation of total tactile sensations in virtual reality. | en_US |
| dcterms.extent | 199 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2025 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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