Abstract
The skin acts as the most significant barrier against external infections, and the healing process of the skin is highly complex and vital. Chronic wounds not only heal slowly but can also cause a range of serious complications that can lead to life threatening consequences. Billions of dollars have been invested in researching ways to accelerate wound healing. Traditional wound dressings only function to prevent outer infection, but they have many limitations and do not accelerate wound healing. Electrical stimulation (ES) has been demonstrated to accelerate tissue growth and cell migration. Therefore, recent studies have integrated ES with wound dressings.Other factors, for instance, drug delivery and breathability, were also essential for wound recovery in addition to ES. Therefore, a breathable smart wound dressing has been designed in this work. This wound dressing serves as a platform that can provide ES, deliver medicine to the wound, and collect the wound exudates as analytes for glucose levels.
To accomplish these functions, the wound dressing in this project was designed from the following aspects.
(i) Liquid delivery and breathability: Polydimethylsiloxane (PDMS) has superb biocompatibility and hydrophobicity, making it an ideal wound dressing. However, PDMS cannot allow liquid to pass through, which hinders the transportation of oxygen and blood to the wound. In this study, unidirectional channels were designed to facilitate the delivery of blood and air. Additionally, wound dressing enables the delivery of medicine to the wound. The optimal channel size has been simulated using the finite element analysis software COMSOL. Additionally, the unidirectional liquid delivery ability has also been tested using a contact angle test machine.
(ii) Conductive and mechanical performance: As an insulating material, PDMS needs to be supplemented with additional conductive materials in PDMS-based wound dressings to equip conductivity. Silver has excellent conductivity, and in addition, Ag ions can act on bacteria through a variety of mechanisms, including binding to proteins in the bacteria, damaging the cell structure of the bacteria, and causing the bacteria to die. In this work, silver paste was used to decorate the wound dressing. The shape of silver traces was determined by simulation using COMSOL. Additionally, the performance of silver traces combined with a PDMS base was also simulated using COMSOL. The conductive performance of this wound dressing was recorded under deformation using a stretching machine and a resistance tester.
(iii) Flexible and wearable battery: Although there are many nanogenerators, most commercial wound dressings with ES still use batteries as a power supply source. This is because these nanogenerators have many limitations, including low power density, unstable power supply, and high cost. In this work, a 6.2mm diameter button cell was selected as the power source. The button cell was encapsulated by PDMS, and carbon paper was cut to serve as the conductive electrode.
(iv) (Glucose detection: Blood is an ideal analyte because it contains a wealth of biological information that can reflect the health of the human body. And in the initial wound healing process, there will generate lots of blood from the wound. The wound dressing proposed in this work is mainly used in chronic wounds, for example diabetic wounds. Thus, a blood reservoir was fabricated to collect and analyze the glucose level.
| Date of Award | 15 Jul 2025 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Xu Sun (Supervisor) & Sheng Zhang (Supervisor) |