E-Skin Development and Prototyping via Soft Tooling and Composites with Silicone Rubber and Carbon Nanotubes

The strategy of embedding conductive materials on polymeric matrices has produced functional and wearable artificial electronic skin prototypes capable of transduction signals, such as pressure, force, humidity, or temperature. However, these prototypes are expensive and cover small areas. This study proposes a more affordable manufacturing strategy for manufacturing conductive layers with 6 × 6 matrix micropatterns of RTV-2 silicone rubber and Single-Walled Carbon Nanotubes (SWCNT). A novel mold with two cavities and two different micropatterns was designed and tested as a proof-of-concept using Low-Force Stereolithography-based additive manufacturing (AM). The effect SWCNT concentrations (3 wt.%, 4 wt.%, and 5 wt.%) on the mechanical properties were characterized by quasi-static axial deformation tests, which allowed them to stretch up to ~160%. The elastomeric soft material’s hysteresis energy (Mullin’s effect) was fitted using the Ogden–Roxburgh model and the Nelder–Mead algorithm. The assessment showed that the resulting multilayer material exhibits high flexibility and high conductivity (surface resistivity ~7.97 × 104 Ω/sq) and that robust soft tooling can be used for other devices.

Maximum Swelling of the Surface of the Composite Material

This article proposes a method for quantitative assessment of a multilayer material interaction with a solvent. It is proposed to assess the effect of solvents on the material by the value of its surface's maximum swelling. The advantage of this method is that the determined value of the outer layer's maximum surface swelling does not depend on the time of swelling and is least influenced by the properties of lower layers.

Perspective Composite Material Made of Volume Fabric - Experimental Tests

In all industries, composite materials with a multilayer structure are widely used. Each layer of the composite material is a directional fiber impregnated with a binder polymer. Layered composite materials, possessing unique properties and high manufacturability, have a significant drawback - the presence of interlayer defects in material, which reduces the scope of their application. One of the perspective directions for reducing the process of interlayer fracture in composite materials is the use of bulk textile material, which is the reinforcement of the entire multilayer material. This article presents an overview of some researches that provide basic information about the creation of perspective composite material made of volume fabric and materials based on them. We provided open information about manufacturers of 3D fabric materials. We carried out experimental tests with composite materials, which showed that material with transverse threads is 30-35% stronger during end impact than a composite material without reinforcement.

Study of multilayer material deformation conditions by method of finite element analysis

The finite element analysis method of multilayer materials deformation during hot rolling is studied. Physical conditions, on which the model is based, is described. Calculation results showed the multilayer materials center of deformation singularity and difference from condition of blank edge. It is shown that uniform deformation of multilayer material during hot rolling is possible due to formation of layer bonding. Described results are useful for multilayer materials on the base of different metals.

Application of Polypropylene-Based Nanocomposite Films for Sliced Turkish Pastrami under Vacuum/Modified Atmosphere Packaging: A Pilot Study

The purpose of this study was to investigate the effects of polypropylene (PP)-based nanomaterials with improved barrier properties by nanoclay and antimicrobial properties by poly-beta-pinene (PβP) on the quality and shelf life of sliced pastrami as an alternative to the commercial multilayered materials. Sliced pastrami was packaged using nanocomposite films with and w/o PβP, and multilayered material under air, modified atmosphere packaging (MAP) and vacuum. Packaged products were screened for microbiological, physicochemical and sensory quality at 4 °C for 6 months. Salmonella spp., Clostridium perfringens and coagulase positive Staphylococus aureus were not detected in the products during entire storage. No yeast and mold growth occurred for entire storage using antimicrobial nanocomposite and multilayer material under vacuum. The antimicrobial effect of PβP on the pastrami was higher under vacuum compared to MAP applications suggesting that direct contact of the material is required with the food surface. Thiobarbituric acid reactive substances (TBARS) of pastrami under vacuum were lower than those of MAP applications. The initial carbonyl content of the product was determined as 3.38 nmol/mg and a slight increase was observed during storage period for all applications. The shelf life of pastrami is suggested as 150 days using PβP containing nanomaterials under vacuum, which is longer than the shelf life of a commercial product on the market using multilayer materials.

VARIASI TEMPERATUR TERHADAP PERUBAHAN NILAI KEKUATAN SEAL PADA MATERIAL KEMASAN LENTUR MULTI LAYER PET-ALU FOIL-LDPE

Plastic is common flexible material for packaging. One of common combination multilayer material are PET-ALU FOIL-LDPE. Multiplayer packaging through some step. Last steps is bag making. Bag making was processed with sealing inner plastic material in certain position with heat. Transverse direction (TD) for horizontal seal and Machine Direction (MD) for horizontal seal. The aim to gain a good seal strength is to avoid broken while filling process. Some factors that affect seal strength are temperature, time and pressure of sealing process. This research focus on seal strength value while temperature changed. Temperature starts from 140C to 240C with interval 20C. This experiment gained two optimum temperature and seal strength for TD and MD. Seal strength TD is 31 N/mm at 180C and seal strength 34 N/15mm at 160C for MD.

Study of Elemental Depth Distribution in the Multilayer Material \(\text{TiO}_2\)/\(\text{SiO}_2\)/Si by Rutherford Backscattering Spectrometry (RBS)

In this study we investigated depth distributions of elements in the multilayer structures of TiO\(_2\)/SiO\(_2\)/Si before and after ion irradiation. The samples were implanted with Ne\(^+\), Ar\(^+\), Kr\(^+\) and Xe\(^+\) ions. For each implantation the multilayer structures were irradiated by the ions with the energy 100, 150, 200 and 250 keV. The elemental concentrations in the samples were analyzed by the Rutherford Backscattering Spectrometry (RBS) method. It was found that the transition layers existed between the TiO\(_2\) and SiO\(_2\) layers. Formation of these layers derived from the ion beam mixing that was occurred at TiO\(_2\)/SiO\(_2\) interface after irradiation process. The depth profiles show that thickness of the transition layers increased with the growing energy and atomic mass of the implanted ions.

Strengthened Layered Polymer-Knitted Films And Coatings

The article presents the results of a study of the properties of a new multi-layer reinforced composite material based on polyethylene and mesh knitted fabric. The physical and mechanical and operational properties of the reinforced polymer laminates depend on the type of raw material, the geometric dimensions and shape of the lumen of the mesh knitted fabrics, on the methods and modes of formation of the multilayer material.