Antal Huba

The Comparison of Solid Silicone Rubber Types Manufactured by Diverse Technologies

The paper presents the current results of our ongoing research on the field of silicon rubber applications in precision engineering and in medical industry. We have demonstrated two technologies for the manufacturing of precision parts and devices for the medical industry. The mechanical properties of the silicone rubber materials manufactured by press vulcanisation and by moulding (diving) are compared.

Dynamic Analysis of Silicone Elastomers

The silicone elastomers offer in our days new perspective for the construction in the precision engineering and in the medicine because of their special mechanical, electrical, optical and chemical properties. Since the essential material parameters like storage modulus and loss modulus depend on temperature and frequency explicit it is important for simulations to know these characteristics. This report is about determining of relaxation behaviour of silicone rubbers and about finding the mathematical relation to describe time-temperature equivalence of silicone elastomers. As conclusion we can declare that the common used Williams–Landel-Ferry equation to describe temperature and time dependent behaviour of polymers is not applicable for silicone rubbers.

Dynamic Models of Silicone Rubbers Based on the Synthesis Method

The silicon elastomers offer in our days new perspective for the c onstruction in the precision engineering and in the medicine because of their speci al mechanical, electrical, optical and chemical properties. Since the essential material paramete s and dynamic models of this materials are only partially and not exactly known for the CAD and for the FEM simulations it was important to estimate this characteristics. For the identifica tion of the dynamic model of this material we used the method of synthesis well known for the calc ulation of passive electric filter (impedance) networks. We found with help of this method a precise descr iption of the phenomenological modeling of the behavior of silicon rubbers since the mea sured data have been used for the mathematical operations.

Impedance Analysis of Silicone Rubber Filled by Electrically Conductive Nanoparticles

During the research, scanning electron microscopy, compression, tensile and frequency analysis were performed on silicone rubbers filled with conductive particles , in order to understand the electrical conduction mechanism. The distribution of the conductive nanoparticles and its relationship with the substrate was examined with scanning electron microscopy (SEM). During the SEM studies, the conductive elastomers were investigated in their deformed and original state too. The connection between the deformation and the resistivity was examined with compression and tensile tests. The impedance of the material was examined on a wide range of frequency. The correctness of the lumped parameter model that is mentioned in the literature , was examined and its parameters were determined. The dependence of the resistivity on the aspect ratio of the specimens was also investigated. The aim of this research is to make this construction material intelligent, and to use it to produce hyperelastic mechanical sensors (for strain, force, torque, ect. measuring).

Measuring of Equibiaxial Tension of Rubber-Like Materials by Optical Method

For the simulations of elastic constructions actuated by inner pressure we need for the definition of the material model parameters, the data originating from the biaxial test. The paper reviews the biaxial material testing methods, especially the bubble inflation methods. It contains a short summary of the stress analysis of the rotation ellipsoid shells in association with the bubble inflation. The paper shows a developed equibiaxial inflating test using optical measurement method. Two different methods using image processing are showed. The test result of an examined silicone rubber (MED-4930) is presented with it’s material parameters.

Mechanical Testing of Tendon

This paper presents an overview about results of mechanical testing of human tendon. We are dealing with the main function of tendon and touching on typical insurance of tendon and reconstruction of them. Since the material characteristic of tendon and dynamic models of them are not known there was made a lot of uniaxial tension test and based on measuring results built up a linear lumped model for dynamic simulation using the synthesis method. As results we can already provide quantitative data about mechanical bearing capacity of tendon beside known qualitative categories. Paper shows a well working fixing technology for tendons during tension test.

High Elasticity Strain Gauge Made from Conductive Silicone Rubber

The paper summarises the results of our investigations on the conductive silicone rubber as strain sensor. The dynamic behaviour of silicone rubber shows strong nonlinearity and because of the relaxation and creep the sensor can not be used for static measure. The greatest advantage of this material lies in its high elasticity. The commercial strain metallic or semiconductor gauges work in the range of 10-7<ε<10-3 . With the new silicone rubber sensor one can achieve elongations typically in the range of 10-2<ε<102 so this sensor offers new possibilities for the measure and control of high elasticity structures. The fatigue tests show that dynamic behaviour of the sensor silicone is stable.

Influences of Manufacturing Technology on the Mechanical Properties of Silicone Rubber Structures

The paper presents the results of investigations made to clear how the different manufacturing technologies of silicone rubber structures affect the mechanical properties of the products. The problem is not obvious since there are numerous devices produced especially for the health care. We also controlled extreme high purity silicone rubbers and compared the results with data measured on simple industrial silicone rubbers. The aim was to see the difference between expensive medical materials and normal ones to simplify the fatigue tests and to decrease the costs of other mechanical investigations.

High Elastic Bionic Based Robot and Gripper

The aim of our research activity is to analyse and develop several new types of compliant structures such as new types of flexible actuators and grippers made from silicone elastomers. Nowadays these materials offer new perspective for the construction because of their special mechanical, electrical, optical and chemical properties