Application Note | ElastoSens™ Bio
Measuring mechanical properties of brain tissue using ElastoSens™ Bio
Introduction
The brain’s ability to regulate cognitive, sensory, and motor functions depends not only on its complex network of neurons and signaling pathways but also on the unique mechanical behavior of its tissue. Brain matter is exceptionally soft, heterogeneous, and sensitive to deformation, which makes its mechanical properties central to both normal function and vulnerability to injury. By studying these properties, scientists and clinicians can better understand how a healthy brain functions, detect early signs of disease, and design therapies that restore or preserve performance.
Key mechanical properties of brain tissue
Elasticity
Elasticity reflects how brain tissue resists deformation and returns to its original shape after stress. It is a fundamental property that helps maintain structural integrity during physiological processes such as blood flow pulsation or minor head movements.
Stiffness
Stiffness is a measure of the brain’s resistance to applied force and is highly variable across regions, influenced by factors such as tissue composition and hydration. It plays an important role in distinguishing gray matter from white matter and in guiding computational modeling of brain deformation.
Viscoelasticity
Brain tissue exhibits both solid- and fluid-like behavior, known as viscoelasticity. This property is essential for understanding how the brain responds to dynamic loading, such as impacts or vibrations, and is often studied through oscillatory shear testing and rheometry.
Anisotropy
The brain is not mechanically uniform; its response to stress depends on the orientation of fibers and structures, especially in white matter tracts. This anisotropy has important implications for modeling injury mechanisms and interpreting mechanical tests.
Relationship between diseases and mechanical properties of brain tissue
Traumatic Brain Injury (TBI)
Mechanical properties are critical in understanding traumatic brain injury, where rapid loading leads to excessive shear and strain. Studying viscoelasticity and fatigue behavior of brain tissue provides insight into how repeated impacts affect tissue integrity and long-term outcomes.
Alzheimer’s Disease and Dementia
Changes in stiffness and elasticity have been linked to neurodegenerative processes. Mechanical alterations can reflect tissue degradation and loss of structural organization, making biomechanics a promising tool for early detection and monitoring of dementia-related conditions.
Brain Tumors
Tumors alter local stiffness and viscoelastic properties of brain tissue, which can be detected through imaging-based elastography. These mechanical changes assist in diagnosis and surgical planning by highlighting abnormal regions compared to healthy tissue.
Epilepsy
Abnormal mechanical responses have been reported in epileptic tissue, where regional changes in stiffness may be associated with altered neuronal and structural organization. These differences can help guide treatment strategies and advance understanding of epilepsy as a biomechanical as well as neurological disorder.
How brain tissue mechanics are assessed
In Vivo techniques (Clinics)
In clinical contexts, non-invasive imaging has become the main avenue for assessing brain mechanics. Magnetic resonance elastography (MRE) and ultrasound elastography are two widely used modalities that generate mechanical waves and capture tissue deformation to estimate stiffness and viscoelastic parameters. These approaches provide valuable information about brain health, support diagnosis of neurological diseases, and allow repeated measurements over time without invasive procedures. In addition, intra-operative methods, such as aspiration-based devices, can be applied during neurosurgery to probe local elasticity directly, offering real-time feedback about tissue properties in the surgical field.
Ex Vivo techniques (Research)
In research settings, a broader set of mechanical testing tools is applied to characterize brain tissue under controlled laboratory conditions. Common approaches include atomic force microscopy (AFM) for probing mechanical properties at the micro- and nanoscale, indentation tests for localized stiffness and viscoelasticity, and axial mechanical testing for uniaxial tension, compression, or shear. More specialized methods, such as oscillatory shear testing and rheometry, provide insights into frequency-dependent viscoelastic behavior. These ex vivo instruments allow precise evaluation of tissue responses, help calibrate computational brain models, and improve our understanding of how structural organization and mechanical loading influence brain function.
Case study: Brain tissue mechanical characterization with ElastoSens™ Bio
ElastoSens™ Bio: a contactless tool for Ex Vivo tissue testing
In the study of brain biomechanics, the ElastoSens™ Bio offers a novel solution for ex vivo assessment. This instrument enables continuous, non-destructive measurement of viscoelastic properties, maintaining the delicate integrity of brain samples throughout testing. Its technology supports accurate characterization of ultra-soft tissues and allows repeated evaluations under controlled environmental conditions, complementing and extending the insights gained from conventional mechanical methods.
To demonstrate the potential of the ElastoSens™ Bio, we performed an ex vivo investigation on brain tissue specimens. The following section presents the materials and methods applied in this study, followed by the results, serving as a practical example of the instrument’s application.
Material and methods
Brains from pork and sheep were collected from a local farm. Cylindrical-like tissue samples (23 mm internal diameter, variable height) were obtained with a biopsy-like punch. Each sample was secured in the macro holder of the ElastoSens™ Bio instrument, and measurements were performed at room temperature for one minute.
The device provided continuous monitoring of viscoelastic parameters, namely the shear storage modulus (G′) and shear loss modulus (G″). For each condition, data are presented as the mean of five independent specimens, taken from the same anatomical region of five different brains (n=5).
Figure 1. Brain tissue sample.
Results and discussion
Using the ElastoSens™ Bio non-destructive testing system, Figure 2 shows that pig brain tissue exhibited a higher shear storage modulus (G′ = 703 ± 45 Pa) compared to sheep (650 ± 160 Pa), indicating slightly greater stiffness and elastic energy storage. In contrast, pig tissue also showed a higher damping ratio (Tanδ = 0.49 ± 0.02 vs. 0.35 ± 0.01), reflecting greater viscous energy dissipation. These findings suggest that while the stiffness of sheep and pig brain tissue is comparable, pig brain tissue exhibits a more dissipative mechanical response.
Our pig brain values are in line with previous studies using oscillatory shear testing and rheometry, which reported porcine brain shear moduli between 500 and 1600 Pa (Thibault et al., 1998; Wismans et al., 1999; Hrapko et al., 2008). For sheep, rheometry of ovine brain tissue reported storage modulus values below 1313 Pa in cerebellar samples as diagnostic thresholds for post-mortem changes (Zwirner et al., 2024). The ovine values thus fall within a similar low-kPa range, although they were obtained under forensic testing conditions where storage temperature and handling influence the results. Overall, the ElastoSens™ Bio applies standardized hydration and loading without destructive handling, improving repeatability and preserving physiologically relevant viscoelastic properties of neural tissue.
Figure 2: Viscoelastic properties of brain tissue for sheep and pig: shear storage modulus (G′) (left) and damping ratio (Tan𝛿) (right) obtained with the ElastoSens™ Bio non-destructive testing system (mean ± SD, n=5).
Conclusions and perspectives
The elasticity, stiffness, viscoelasticity, and anisotropy of brain tissue are key to understanding both neural function and pathological transformations. Results from this study show that the ElastoSens™ Bio enables reliable, non-destructive measurement of brain mechanics, capturing important viscoelastic parameters including shear storage modulus (G′) and shear loss modulus (G″). This method provides reproducible, high-quality data, supporting rigorous comparisons between species and experimental models.
Furthermore, the ElastoSens™ Bio delivers distinctive benefits for neuroscience and biomaterials applications:
- Simple preparation and setup minimize manipulation of delicate brain tissue, preserving hydration and microstructural integrity during testing.
- High sensitivity and repeatability ensure consistent measurements across regions (e.g., cortex, hippocampus, white matter), capturing the inherent variability of brain mechanics.
- Cross-species benchmarking enables translational research by directly comparing brain tissue properties from animal models with human data.
- Platform versatility supports testing of diverse neural tissues and biomaterials under identical conditions, facilitating the development of implants, scaffolds, or hydrogel-based therapies.
- Engineered tissue applications benefit from non-destructive, longitudinal measurements that track the evolving properties of bioengineered brain constructs and organoid models.
- Controlled incubation and repeated testing allow monitoring of viscoelastic changes over time, reflecting processes such as tissue degradation, pharmacological response, or disease progression.
Together, these attributes establish the ElastoSens™ Bio as an essential instrument for advancing brain tissue mechanics, comparative studies, and engineered tissue research.
References
Hou, J., Jiang, K., Ramanathan, A., Kumar, A. S., Zhang, W., Zhao, L., … & Wang, X. (2025). Mechanical Characterization of Brain Tissue: Experimental Techniques, Human Testing Considerations, and Perspectives. arXiv preprint arXiv:2504.12346.
Faber, J., Hinrichsen, J., Greiner, A., Reiter, N., & Budday, S. (2022). Tissue‐scale biomechanical testing of brain tissue for the calibration of nonlinear material models. Current Protocols, 2(4), e381.
Lilley, R. L., Kabaliuk, N., Reynaud, A., Devananthan, P., Smith, N., & Docherty, P. D. (2024). A Novel Experimental Approach for the Measurement of Vibration-Induced Changes in the Rheological Properties of Ex Vivo Ovine Brain Tissue. Sensors, 24(7), 2022.
Thibault, K. L., & Margulies, S. S. (1998). Age-dependent material properties of the porcine cerebrum: effect on pediatric inertial head injury criteria. Journal of Biomechanics, 31(12), 1119–1126.
Wismans, J. S., & Paas, M. H. (1999). Comparison of the dynamic behaviour of brain tissue and two model materials. Journal of Biomechanics, 32(10), 1079–1085.
Hrapko, M., Van Dommelen, J. A., Peters, G. W., & Wismans, J. S. (2008). The influence of test conditions on characterization of the mechanical properties of brain tissue. Journal of Biomechanical Engineering, 130(3), 031003.
Zwirner, J., Devananthan, P., Docherty, P. D., Ondruschka, B., & Kabaliuk, N. (2024). The influence of cooling on biomechanical time since death estimations using ovine brain tissue. International Journal of Legal Medicine, 138(9), 2541–2549.
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