| Author: | Ma, Xiaohao |
| Title: | Monolithically integrated in-textile patch for wireless epidermal biosensing |
| Advisors: | Zheng, Zijian (ABCT) |
| Degree: | Ph.D. |
| Year: | 2026 |
| Subject: | Wearable technology Biosensors Wound healing Electronic textiles Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Applied Biology and Chemical Technology |
| Pages: | 1 volume (various pagings) : color illustrations |
| Language: | Chinese |
| Abstract: | Recent advancements in wearable bioelectronics underscore the demand for multifunctional, breathable systems capable of continuous and non-invasive health monitoring. It is highly challenging to develop epidermal biosensing devices with desirable permeability, biocompatibility, and the ability to track both physiological and pathogenic markers simultaneously. This thesis presents several in-textile systems for wireless and real-time biosensing, combining sweat analysis and wound microbial detection into a permeable bioelectronic platform. By utilizing textile-compatible fabrication processes, the biosensing systems can be seamlessly integrated into textiles, providing the attributes of wearing comfort, durability, and conformability to skin deformations during daily activities. First, a novel photolithography approach designed explicitly for textiles enables uniform and precise metal patterning directly within porous fabric architectures. This method achieves sub-100 µm resolution on yarns, circumventing challenges posed by textile pore dimensions and capillary-driven diffusion within yarn structures. The resulting metal patterns exhibit exceptional mechanical resilience (withstanding 10,000 bending cycles) and laundering durability (20 washes) with minimal change in conductivity. Furthermore, this technique facilitates controllable metal permeation throughout the textile scaffold, significantly enhancing performance and enabling the dual-sided integration of miniaturized electronic devices, while maintaining essential fabric permeability and stability. Second, a fully integrated fabric wristband incorporating multifunctional modules demonstrates wireless sweat biosensing capabilities. Utilizing precisely patterned conductive elements within the textile structure, coupled with robust interconnection encapsulation, achieves electrical performance, mechanical durability, and liquid resistance comparable to conventional flexible electronics. Critically, the preserved porous nature of the fabric substrate provides exceptional wearing comfort, evidenced by air permeability (79 mm s⁻¹) and moisture vapor transmission rate (270 g m⁻² day⁻¹) significantly exceeding those of standard medical adhesives. This integrated platform successfully monitored sweat potassium levels (0.3-40 mM range) with sustained stability, highlighting its suitability for fitness tracking and point-of-care diagnostics. Expanding on this, a multiplexed textile-based sensing system was realized, incorporating signal-conditioned wireless data transmission (Bluetooth Low Energy) for simultaneous detection of pH, sodium (Na⁺), potassium (K⁺), glucose, and lactate. On-body validation during physical activity showed excellent concordance (R² > 0.99) with standard reference measurements for potassium. This approach overcomes key hurdles in device-skin interface stability and user comfort, offering a scalable manufacturing route for non-invasive health monitoring platforms. Finally, a wound monitoring patch was constructed using aptamer sensor arrays integrated onto a breathable textile substrate. This platform facilitates the continuous, multiplexed detection of key wound exudate biomarkers, including pH, the bacterial infection indicator TNF-α, the fungal marker β-1,3-glucan, and the inflammation-associated cytokine IL-6. This fabrication method ensures high-resolution patterning while maintaining essential textile properties: moisture vapor transmission exceeding 290 g m⁻² day⁻¹ and mechanical flexibility. Microbial identification leverages TNF-α for bacterial presence and β-1,3-glucan for fungal detection. Validation yielded a relative standard deviation (RSD) of 21% for mouse TNF-α quantification, demonstrating the viability of this integrated textile-based sensing platform for non-clinical wound management applications. In conclusion, this thesis first demonstrated a popular and promising in-textile photolithography method for fabricating metal patterning (Cu, Ni and Ag) on fabric structures. Then it introduced an in-textile wristband that offers exceptional flexibility, permeability, biocompatibility, and waterproof properties. Subsequently, a multiplexed system involving five sensors (pH, K⁺, Na⁺, glucose, and lactate) was developed to produce complex signal processing and transmission with high mechanical stability and superior conductivity. Finally, a monolithic wound patch was proposed to identify microbial infections, such as bacteria and fungi, showcasing its potential for daily wound monitoring and early warning. It is envisioned that this thesis will provide practical and universal solutions for the development of monolithically integrated in-textile bioelectronics. |
| Rights: | All rights reserved |
| Access: | open access |
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