Laboratory of Biomechanics

Head of Laboratory

Zlámal Petr, Ing., Ph.D.

Reserach Activities

Laboratory of biomechanics supports research activities of the Department of biomechanics particularly in terms of the experimental determination of mechanical characteristics of biological materials and artificial biocompatible structures by various micro-mechanical loading procedures and radiographical methods. The Laboratory provides facilities not only for the experimental research, but also for design, commissioning and testing of innovative testing equipment and state-of-the-art evaluation procedures.

Experimental Equipment (current)

• Modular uni-axial loading device for radiographical and optical measurements with loading capacity up to 10 kN (proprietary design)

Compact uni-axial loading device with loading capacity up to 10 kN and interchangeable load bearing frame manufactured either from high-strength polymer or from carbon-fiber composite suitable for both optical or radiographical measurements of deformations. Motorized loading axis with movement range of 22 mm can be equipped with different load cells according to requirements of the respective experiment.

• Uni-axial loading loading device for optical and radiographical measurements with loading capacity up to 0.5 kN (proprietary design)

Compact uni-axial loading device with loading capacity 0.5 kN and plexiglass load bearing frame suitable for radiographical measurements with the possibility of optical strain determination. Motorized loading axis with movement range of 20 mm can be equipped with different load cells according to requirements of the respective experiment. The device is primarily intended for measurements of trabecular bone samples and samples of tissue scaffolds.

• Loading device for radiographical measurements of four-point bending experiments suitable for investigation of quasi-brittle materials (proprietary design)

Compact loading device for four-point bending experiments with loading capacity 2x 1.25 kN (1.25 kN per single loading support) and carbon-fiber composite load-bearing frame suitable for radiographical measurements. The device is composed of two loading units capable of precise synchronized movement, encoder-based readout of position, and readout of the measured force. Maximum length of samples is up to 300 mm. Cables for control, measurement and power signals are plugged into rotary slip ring connector to achieve possibility of unlimited number of rotations of the device during tomographical measurements.

• Uni-axial loading device for optical and radiographical measurements with optional bio-reactor chamber and loading capacity up to 3 kN (proprietary design)

Compact uni-axial loading device with loading capacity 3 kN and interchangeable load bearing frame manufactured either from aluminium alloy or from carbon-fiber composite suitable for both optical or radiographical measurements of deformations. Positioning of the loading axis (with 30 mm movement range) is performed using high-precision ball-screw and 4 guide ways forming linear guide assembly with 20 um movement accuracy. The device can be optionally equipped with bio-reactor chamber capable of stable fluid flow with selected temperature for simulation of in-vivo conditions. Cables for control, measurement and power signals are plugged into rotary slip ring connector to achieve possibility of unlimited number of rotations of the device during tomographical measurements.

• Modular electronic system for control of experimental devices (proprietary design)

System for control of experimental devices capable of precise and reliable simultaneous control of up to 5 axes. The electronics also performs readouts of physical quantities related to the respective experiment (force, temperature, fluid flow, etc.). The system is mobile and suitable for effortless measurements at other laboratories. The system is compatible with all proprietary devices at the department.

• Software for control of experimental devices - RAPO (proprietary development)

Software for control of experimental devices developed at the Department of biomechanics based on a community project LinuxCNC. RAPO software is extension of real-time linux kernel with LinuxCNC environment and enables to control developed loading devices in order to satisfy their specific needs. Core and all plugins are implemented in Python programming language, graphical user interface uses Qt5 toolkit. Main features from machine control point of view are: movement of all axis to define position, experiment force and displacement control, cyclic loading, readout and logging of physical magnitudes and their real-time plotting, etc. Integral parts of RAPO software are also routines for safety operation of loading devices: overload switch, software axes limit switch, etc.). Function configuration and interface customization for the specific loading device is easily performed using a configuration file.

• Three-axis translation stage (proprietary design)

High-precision motorized three-axis translation stage for positioning of optical systems based on an assembly of three individual linear stages.

Loading device for creep tests (proprietary design)

Device based on lever mechanism for long-term tensile loading of samples at elevated temperatures with force and displacement readout and the possibility of optical strain measurement.

• CCD camera with bi-telecentric zoom lens

A pair of CCD monochromatic cameras equipped with GigE interface and C-mount for attachment of machine vision lenses; bi-telecentric lens with 4 magnification levels.Zatěžovací stolice Instron 4301

• Universal testing system Instron 4301
  

Electro-mechanical testing system for uni-axial compressive/tensile tests equipped with 1 kN or 5 kN load cell. The device can be optionally equipped with thermal chamber for testing of materials at elevated temperatures.

• Anti-vibration table
  
• LED cold-light illumination system for optical measurements

Equipment under construction

• Device for optical and mechanical analysis using gradual abrading

Device for optical and mechanical analysis using gradual abrading and micro-hardness measurement. The device integrates functions of a precise grinding, a microindentation and an optic inspection and image analysis without removing a sample out of the device and loss its reference position. Combining the entire workflow enables to determine material hardness distribution in whole volume of the sample with approximately 10 um vertical resolution.