Novel Body-conforming Photonic Textile Material for Therapeutic Application of Wound Healing
Creators: name: Shekhar, Ravi
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 401605
subject: Functional materials

description: The aim of this study was to engineer a light therapy photonic textile material capable of conformin gto the curves of the human body and capable of irradiating light with attributes suitable for accelerated wound healing and scar reduction. Bio-photonics aims to address dermatological and skeletomuscular issues through the application of light therapy. A low level of light therapy is useful for reducing inflammation, assuaging chronic joint pain, and accelerating a wound’s healing process by preventing tissue death and aiding tissue repair. However, the literature review shows some limitations, one of which is heterogeneity in the light’s irradiance, mainly when applied to the human body’s curved surfaces. The second is the portability of these therapeutic devices. Some researchers speculate that a lightweight, flexible light-emitting material that can conform to the shape will overcome these limitations. Researchers have used various materials, from flexible light-emitting diodes to optical fibre fabric, while testing light therapy’s efficacy on a wound. However, there is no substantive literature on these materials’ attributes for flexibility and functionality and no evidence on the photonic textile material’s development for wound therapeutic applications.
As these devices are designed for other specific purposes, they do not conform with the flexibility and thickness requirement of wound healing photonic materials. Availability of wound healing photonic material is limited to research only and reported in research publications but is not commercialised. These knowledge gaps inspired the assessment of the existing photonic materials for flexibility and functionality. This research reviewed and established the values of key optical characteristics such as wavelength, power density, and dose range of the light therapy devices used for accelerated wound healing. This research also established methods of testing to analyse and benchmark these characteristics. This benchmarking method was curated using standard methods and tools prevalent in photonic science and textile technologies. This benchmarking method was later used in evaluating photonic materials to assure future repeatability of a similar assessment. Later, the optical, electrical, and structural characteristics of existing light-emitting flexible materials and candidate components, which promises to meet the values of key optical characterise as established in the literature review,were benchmarked.
Through literature review, the most effective wavelength within the visible spectral window was found to be 630nm with a prominent dose range of 1 to 5 Jcm-2at treatment intervals of 10 to 30 minutes. Following the optical characterisation, Surface Mounted Light-Emitting diode(SMD LED)0402of dimension 1.0mm X 0.5mm X 0.5mmwas selected as a suitable photonic candidate material to explore photonic materials’ integration methods into a textile. After a preliminary investigation into different fabrication techniques, manual weaving was established as a fabrication method to integrate this selected photonic candidate component into novel flexible textile materials. Later, two developed prototypes of novel flexible photonic textile materials were characterised and compared for their optical, electrical, and structural characteristics. Prototype 1 established the proof of concept that a flexible photonic textile material can be developed through a textile material development process, while Prototype 2 established that optical and electrical characteristics are suitable for therapeutic application. However, Prototype 2 had structural limitations,such as the elasticity of the selvedge material. After sampling eighteen yarn combinations of elastomer and stainless-steel yarn, one elastic conductive yarn (ECY) was selected as selvedge material for Prototype 3. Finally,Prototype 3, as the novel body-conforming photonic textile material for therapeutic application of wound healing,wasevaluated for optical, electrical, and structural characteristics. 
Prototype 3 integrated with ECYwith better elasticity demonstrated 40% extension until the first filament breakin the conformability test. In comparison to commercial bandages, the structural characteristics of the Prototype 3 were found to be comparable with the potential scope of improvement. These included 16% higher air permeability, 60% higher absorptive capacity, 185% higher extensibility, 7.7% higher bending length, and 684% higher flexural rigidity than that of commercial bandage. In the optical, electrical, and thermal evaluation, Prototype 3 proved to radiate 3.2 Jcm-2in approximately 17 minutes with a dominant wavelength of 630 nm at optical efficacy of 1.66% while operating on 3.2 volts. The total current drawn was approximately 600 mA for twenty SMD LEDs,and the illumination area was 10 cm2. Consequently, for 30 minutes of treatment with a treatment area of 10 cm2, a 300 mAh battery was calculated to suffice the energy need of Prototype 3, making it portable. In the thermal testing, it was evident that at higher voltage input, optical irradiation is higher,and therefore surface temperature of elastic photonic bandage is higher as well. Additionally, prototype 3,with a peak temperature of 28°C when switched on and 22°C when switched off, suggests a 6°C temperature rise. Nevertheless, as compared to the surface temperature of healthy human skin,which is 33°C, a therapeutic device with a 6°C surface temperature rise, translates surface temperature of a maximum of 39°C on the human body,which is expected not to have any discomfort and opens a gateway for application into other related light therapies.