BioTester – Biaxial Tester

A fully equipped biaxial test system built specifically for biomaterials 

Biaxial testing is critical for understanding the mechanical properties of biomaterials due to their directionally oriented microstructures.  The BioTester system has been designed to make biaxial testing simple so that users can focus on results rather than testing.

Key Features

  • 4 high performance actuators with inline load cells
  • High resolution CCD imaging with image-based strain measurement tools
  • Several attachment options including patented BioRakes for fast and reliable specimen mounting
  • Integrated temperature controlled media bath
  • Fully featured user interface software for simple, cyclic, relaxation, and multi-modal testing with real-time feedback

Specimens & Mounting

The BioRake sample mounting system is CellScale’s patented method for attaching soft tissues and biomaterials.

Each tine is electrochemically sharpened to easily pierce both the toughest and most delicate tissue samples. Each set is permanently attached to a common base to allow simultaneous puncture of all 20 attachment points. The BioRakes are magnetically mounted for easy removal for cleaning or replacement and for simple transition between BioRake, Balanced Pulley, and Clamp mounting systems.

To perform testing, samples are positioned and raised into place using the manual lift mechanism and pressure is applied to insert the hooks in the tissue. The sample is thus mounted and ready for analysis within a few seconds. The mounting is consistent, accurate and easy.

BioRakes are available with tine spacing ranging from 0.7mm to 2.2mm to accommodate specimens from 3 to 15mm in size.

BioRake Sample Mounting System

The balanced pulley sample mounting system is CellScale’s attachment method for ensuring zero shear stress during biaxial testing.

Two double-ended custom suture hooks are used to create 4 attachment points on each side of the specimen. A two-stage stainless steel pulley mechanism ensures that each of the sutures is held at the same tension during the test.

The pulley mechanisms are magnetically mounted for easy removal for cleaning and for simple transition between BioRake, Balanced Pulley, and Clamp mounting systems.

Balanced Pulley Mounting System

The clamp sample mounting system is CellScale’s attachment method for testing to failure.

Using a cruciform specimen allows the attachment sites, which are inherently weaker than the base material, to be moved away from the gauge area of the specimen. The clamps allow the specimen to be loaded easily and held securely.

The stainless steel clamping mechanisms are mounted over the same brackets used for the other attachment systems to allow for fast and easy transition between BioRake, Balanced Pulley, and Clamp mounting systems.

Custom clamp designs can also be made to tailor the clamp force and clamping surface to your tissue.

Clamp Mounting System


The BioTester’s setup, operation and data collection software module allows for simple execution of standard or customized test protocols.

Test parameters such as displacement magnitudes, durations and data/image collection rates are specified in a table format for quick access and modification. Both displacement and force controlled testing can be specified for each axis independently. A template system is used to quickly reload the desired test parameters once a protocol has been established.

The software interface provides live imaging and current force, position, and temperature information to the user during the test setup. While the test is running, the software provides real-time results graphing and a live video feed to facilitate user monitoring of the test progress.

Ask anyone who has used our equipment and they will be quick to tell you how intuitive and useful this software package really is.

BioRake Sample Mounting System

A large part of biaxial testing is understanding and interpreting the collected data.

The BioTester includes an image analysis software module which can be used to review and analyze test images, providing valuable quantitative and qualitative information. This same module can be used to export .avi videos or images with data overlays for presentation purposes.

The BioTester contains a high resolution camera with an excellent visual of the specimen for the duration of the test. The collected images (at a user-specified frequency) are automatically time-correlated with the force displacement data so that the software module can put all the test information at the user’s fingertips.

The image tracking feature of the software module allows test images to be analyzed quickly and easily to determine in-plane motions of one or more points on the specimen surface. This tracking information provides a direct measure of specimen strain rather than relying on strains calculated from grip motion. By tracking a grid of points it is possible to study the strains in different regions of the specimen.

Balanced Pulley Mounting System

BioTester Publications

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What Our Customers Are Saying

Don’t just take it from us, let our customers do the talking!

The CellScale Biotester packs tremendous value and provides unique opportunities toward the standardization of soft tissue biaxial testing and characterization.

Planar biaxial testing of heart valve cusp replacement biomaterials: Experiments, theory and material constants.

Prof. Michel Labrosse

University of Ottawa

The CellScale Biotester offers great flexibility with planar biaxial testing, providing compact and robust hardware setup paired with flexible and capable software. Attachment systems are quick and easy to use, making the device particularly attractive for testing large numbers of specimens…We’ve had great success with CellScale’s customer support, they are very helpful when we have questions and always update us on their new software releases.

Constitutive description of human femoropopliteal artery aging.

Prof. Alexey Kamenskiy

University of Nebraska

We use the CellScale BioTester to characterize mechanical properties of cardiovascular soft tissue. The BioTester provides us with an easy-to-use test instrument and user-friendly interface for post processing. In addition, we are very satisfied with the customer service and support that CellScale provides.

Biomechanical properties and microstructure of heart chambers: a paired comparison study in an ovine model.

Prof. Ali Azadani

University of Denver


Dimensions 60 X 60 X 80cm
Weight 18kg
Force Capacity 23N
Available Load Cells 0.5, 1.5, 2.5, 5, 10, 23N
Force Accuracy 0.2% of load cell capacity
Maximum grip separation 80mm
Maximum Velocity 10mm/s
Maximum Cycle Frequency 2Hz
Maximum Data Rate 100Hz