BioTester – Biaxial Tester

Fully equipped biaxial test systems built specifically for biomaterials

Biaxial testing is critical for understanding the mechanical properties of biomaterials due to their directionally oriented microstructures.  The BioTester systems have 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
  • Several attachment options including patented BioRakes for fast and reliable specimen mounting
  • High resolution imaging with image-based strain measurement tools
  • Integrated temperature controlled media bath
  • Fully featured user interface software for simple, cyclic, relaxation, and multi-modal testing with real-time feedback

BioTester 5000

  • Full feature set included with the standard system
  • Long stroke for up to 80mm grip separation

BioTester 3000

  • Modular design with many optional features
  • Small size with increased access for imaging and other instrumentation

BioTester 6000

  • Increased force capacity to 200N

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

I purchased the Cell Scale biaxial device in my first year as an Assistant Professor. It allowed my first graduate student to start collecting data from day one rather than spend the time to design, build, and validate a custom device first.

The regional-dependent biaxial behavior of young and aged mouse skin: A detailed histomechanical characterization, residual strain analysis, and constitutive model

Assistant Professor Manuel Rausch

The University of Texas at Austin

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


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  BioTester 3000 BioTester 5000 BioTester 6000
Dimensions 46 X 46 X 13cm 60 X 60 X 80cm 78 X 78 X 80cm
Weight 6kg 18kg 23kg
Force Capacity 10N (23N opt) 23N 200N
Available Load Cells 0.5 – 23N 0.5 – 23N 0.5 – 200N
Maximum Grip Separation 50mm 80mm 80mm
Maximum Velocity 20mm/s
Maximum Data Rate 10Hz (100Hz opt) 100Hz 100Hz
Temperature-Controlled Bath Optional Standard Standard
Imaging and Strain Analysis Optional Standard Standard
Test Control Modes Displacement (Force opt) Force, Displacement Force, Displacement