Multi-Point Flexible Temperature Sensor Array and Thermoelectric Generator Made from Copper-Coated Textiles.

The integration of electrical functionality into flexible textile structures requires the development of new concepts for flexible conductive material. Conductive and flexible thin films can be generated on non-conductive textile materials by electroless metal deposition. By electroless copper deposition on lyocell-type cellulose fabrics, thin conductive layers with a thickness of approximately 260 nm were prepared. The total copper content of a textile fabric was analyzed to be 147 mg per g of fabric, so that the textile character of the material remains unchanged, which includes, for example, the flexibility and bendability. The flexible material could be used to manufacture a thermoelectric sensor array and generator. This approach enables the formation of a sensor textile with a large number of individual sensors and, at the same time, a reduction in the number of electrical connections, since the conductive textile serves as a common conductive line for all sensors. In combination with aluminum, thermoelectric coefficients of 3-4 µV/K were obtained, which are comparable with copper/aluminum foil and bulk material. Thermoelectric generators, consisting of six junctions using the same material combinations, led to electric output voltages of 0.4 mV for both setups at a temperature difference of 71 K. The results demonstrate the potential of electroless deposition for the production of thin-film-coated flexible textiles, and represent a key technology to achieve the direct integration of electrical sensors and conductors in non-conductive material.

The wound debrider: a new monofilament fibre technology.

Debridement is a basic necessity to induce the functional process of tissue repair, especially in chronic wounds. In this pilot study the authors used a new debrider technology with specific monofilament fibres in a unique texture to evaluate its efficacy, safety and tolerability. In eleven patients, exhibiting all types of wound-associated debris (biofilms, slough, necrotic crusts and hyperkeratotic plaques), the debrider, wetted with physiological solution, was wiped without specific force over the wound for about 2-4 minutes. This led to removal of almost all debris leaving healthy granulation tissue intact, including small epithelialized islands of vital tissue. The procedure was without pain and adverse events. Scanning electron microscopic analyses identified the majority of the removed debris tightly packed within the monofilament texture. A surgeon who blindly assessed pictures taken before and after the debridement categorized all except one wound without the need for surgical debridement and ranked all the debridement results with the new debrider as 'very good' (best category). This formulates the basic concept that the new debrider-based technology is easy, fast, highly efficient, well tolerated and cost effective.

Sorption of anionic polysaccharides by cellulose.

The sorption of anionic polysaccharides pectin, alginate, and xanthan with cellulose were investigated in presence of calcium. Calcium sorption to cellulose was limited by the carboxyl group content in fibers. Atomic Absorption Spectroscopy (AAS) analysis was used to measure the calcium in cellulose fibers and chemical oxygen demand (COD) analysis reveals that the divalent ions calcium can bind the polysaccharide onto cellulose fibers. The amount of calcium and polysaccharide bound in Ca2+/polysaccharide modified cellulose fibers was 5.8-12.5mM Ca2+/kg fibers and 1500-2400mg polysaccharide/kg fibers, respectively. Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR) analysis confirmed the presence of polysaccharide on calcium containing cellulose fibers. The results of alizarin dyeing experiments at the end of polysaccharide sorption further confirmed the presence of calcium in Ca2+/polysaccharide modified cellulose fibers. The basic phenomenon of interaction of soluble ionic polysaccharide and cellulosic fibers in presence of divalent cations such as calcium is a key to understand biological functions and technological applications.