Mission Statement

Blast induced traumatic brain injury (bTBI) is signature injury in recent combat scenarios involving improvised explosive devices (IEDs). In 2005, the U.S. military reported 10,953 IED attacks, at an average of 30 per day[2].TBI and concussion rates among service members returning from Operation Iraqi Freedom (OIF) have been reported at 22%. However, the rate of persistent symptoms has been reported as significantly lower (8%).


Understanding of the interactions with and transduction of blast waves through complex biological specimen will help elucidate mechanisms of the bTBI. It will result in improvements of the design of personal protective equipment and thus help protect military personnel. The acute and delayed biochemical sequelae of brain tissue injuries caused by blast exposure will aid development of novel, targeted detection and remediation strategies.

Research Objectives

• Study the effects of blast waves or pressure pulses on a human head with and without a protective helmet (experiments and simulation)
• Develop a multiscale constitutive model of helmet, skull, and brain based on experiments and modeling. Simulate the effect of pressure and impact loading on deformation and damage.
• Culture cells, e.g., glial; characterize their dynamic behavior, and study the change in their functional and mechanical responses.

Cell Stretching

The cell stretching project focuses on simulating cell deformation through the use of the Controlled Axonal Injury (CAI) Device. Damaged cell samples are then studied with the use of fluorescence imaging to determine the extent of injury in proportion loading. More »

Raman Spectroscopy

Raman Spectroscopy allows us to analyze the neuron, the main structural and functional component of the brain, to help us understand its biochemical, electrical, and mechanical behaviors under different mechanical loadings. If we define the neuron injury level by these behaviors, we can determine its relationship to the loading level. With this information, we can identify upper and lower damage thresholds as a function of strain and strain rate - important parameters for the designing of helmet effective at preventing bTBI. More »

The RENISHAW Raman Microscope

Blast Wave Modeling With Rats

A supersonic blast wave or shock blast induces an instantaneous increase in atmospheric pressure and causes what is called primary blast injury. Modeling blasts’ effects on rats may help to characterize and understand its mechanisms and so we have begun using three dimensional finite element models of a rat brains and heads to simulate controlled cortical impacts (CCI) and blast loading. Models are developed from MRI images using Avizo© and Mimics13© More »

Shock Tube

Improvised explosive device (IED) is one of the strongest threats in current military operations. IED causes damages in the body of a soldier by applying various external stimuli, e.g., penetration, accelerative loads, overpressure, toxic gases, thermal stimuli, etc. These lead to traumatic damages in various body parts. Among them, traumatic brain injury (TBI) is one of the leading causes of morbidity and death of soldiers. To date, it is not fully understood what physical component of the IED blast causes TBI and how the IED blast induces TBI and its secondary progression at cellular level. In this study, we examine the effects of high pressure impulsive loading, that mimics IED blast conditions, on brain cell response in cell life or death question. We are developing single pulse pressurization equipment (Dr. Feng Group) and assess astrocyte cell response to impulsive pressures in cell proliferation and apoptosis (Dr. Lim Group). More »

Blast Wave Mechanics

Blast induced traumatic brain injury (bTBI) is signature injury in recent combat scenarios involving improvised explosive devices (IEDs). In 2005, the U.S. military reported 10,953 IED attacks, at an average of 30 per day[2].TBI and concussion rates among service members returning from Operation Iraqi Freedom (OIF) have been reported at 22%. However, the rate of persistent symptoms has been reported as significantly lower (8 %). The goal of this research work is to understand role of protective devices like helmet and body armor under blast loading condition and how they relate to blast mitigation... More »

Brain and Skull Modeling

Modeling and simulation activities are becoming increasingly important in the area of brain biomechanics with application to primary blast injury (PBI). Although current FE head models include a detailed geometrical description of the head's intracranial contents, there is a crucial lack of material models for the brain which are appropriate to use in blast scenarios analysis, i.e. over a large strain/ very high frequency range. More »

Cellular Modeling and Experiments

Cultured Neuron Monolayer

The external mechanical load will firstly cause the mechanical deformation of neurons, and then, when this deformation reaches to a critical point (threshold), it will initiate the chemical/biological response. The chemical/biological response can cause the neuronal function loss—neuronal injury. This process is considered to be the mechanism of the mild traumatic brain injury (mTBI) at the cellular level. Understanding the relationship between the neuronal mechanical response and their biological responses is the first important step to understand the mechanism of mTBI. More »

RED Head Design

The ‘RED Head’ or ‘Realistic Explosive Dummy Head’ development project focuses on head injuries caused by shock waves generated by explosions. To develop such a head model, materials analysis was performed to find synthetic materials to simulate human head components such as skin, skull and brain. The geometries of these components were carefully controlled to simulate it as a human head surrogate. The head model was instrumented with various sensors to understand the attenuation of the pressure waves through the brain and the flexure of the skull. More »

The RED Head positioned for the shock tube

Impulsive Pressurization of Neuronal Cells

The Kolsky Bar

Blast-mimicking impulsive pressurization is conducted through use of the Kolsky bar. The direct compression Kolsky bar works by storing strain energy in the bar between the engaged friction clamp and the compressing scissors jack. When the friction clamp is released, by fracturing the locking bolt, the energy in the stored section is released as a near square wave of strain. When the wave reaches an impedance change, such as is at the sample, part of the wave will bounce back while the remainder will pass through the material, in this case an in-vitro cell containment chamber. More »

BioMechanics and Materials Laboratory (BMML)

The research at Biomechanics and materials laboratory at university of Nebraska Lincoln mainly focuses on basic understanding of mechanisms of TBI at various length and time scales using computations and experiments. Unique in house shock tube testing facility along with high fidelity simulations enabled us to investigate and understand wide variety of issues associated with TBI. Laboratory also collaborates with clinicians, biologist and surgeons across the country. More »

People

Associated Projects Blast Wave Modeling With Rats Blast-Helmet Interaction Cellular Modeling and Experiments Brain and Skull Modeling

Blast Simulation Laboratory

People

The research in the Blast Simulation Laboratory at the University of Nebraska–Lincoln mainly focuses on the simulation and measurement of blast waves. In the trauma mechanics research initiative, the blast simulation laboratory focuses on the engineering of the shock tube. This device is the primary means of testing the mechanics of improvised explosive devices (IEDs), the first step for assessing how damage occurs and ways to mitigate it. More »

Associated Projects Shock Tube Design

Blast Cellular Mechanics

Blast Cellular Mechanics focuses on identifying the mechanical properties of neuronal brain cells, especially in blast loading conditions. This research is being done in two directions: using Raman Spectroscopy to analyze the mechanical behaviors of cells after stretching; and using a Kolsky bar set-up to perform controlled pressure bursts then analyzing cell deformation. More »

People

Associated Projects Neuron Pressurization

Biology and Mechanics of Neurons

People

The main goal of the Biology and Mechanics of Neurons research group is to develop an in-vitro platform for the simulation of a broad range of conditions that affect brain tissue when subjected to a traumatic brain injury (TBI). The first stage of the project is to evaluate the cells' response to different levels of injury defined by strain and strain rate and to test the temporal evolution of the damage on a cellular level. More »

Associated Projects Cell Stretching Raman Spectroscopy

Applied Mechanisms and Design Research Laboratory

The Applied Mechanisms and Design Research Laboratory's (AMDRL) primary contribution to the Trauma Mechanics Research Initiative is its work on the RED Head, or the realistic explosive dummy head. This group uses material modeling and analysis to find artificial materials for simulating human head. Instrumentation of the head model will be used to record and analyze blast responses. This data can then validated by a developed mathematical model. More »

People

Associated Projects RED Head Design

In peer reviewed journals

1. V. Selvan, S. Ganpule, N. Kleinschmidt and N. Chandra, "Blast Wave Loading Pathways in Heterogeneous Materials Systems-Experimental and Numerical Approach", Journal of Biomechanical Engineering (2013), accepted. Link pdf
2. P.M. Abdul Muneer, H. Schuetz, F. Wang, M. Skotak, J. Jones, S. Gorantla, M. C. Zimmerman, N. Chandra, and J. Haorah, "Induction of Oxidative and Nitrosative damage leads to Cerebrovascular Inflammation in Animal Model of Mild Traumatic Brain Injury Induced by Primary Blast", Free Radical Biology and Medicine, 60, 282-291 (2013). Link  pdf
3. M. Skotak, F. Wang, A. Alai, A. Holmberg, S. Harris, R.C. Switzer III, and N. Chandra, "Rat injury model under controlled field-relevant primary blast conditions: Acute response to a wide range of peak overpressures", Journal of Neurotrauma (2013), accepted. Link  pdf
4. N. Chandra, S. Ganpule, N.N. Kleinschmit, R. Feng, A.D. Holmberg, A. Sundaramurthy, V. Selvan, A. Alai, "Evolution of Blast Wave Profiles in Simulated Air Blasts: Experiment and Computational Modeling", Shock Waves: An international journal on shock waves, detonation and explosions, 22, 403-415 (2012). Link  pdf
5. S. Ganpule, A. Alai, E. Plougonven, and N. Chandra, "Mechanics of Blast Loadings on the Head Models in the Study of Traumatic Brain Injury Using Experimental and Computational Approaches", Biomechanics and Modeling in Mechanobiology (2012). Link  pdf
6. A. Sundaramurthy, A. Alai, S. Ganpule, A. Holmberg, E. Plougonven and N. Chandra, "Blast-Induced Biomechanical Loading of the Rat: An Experimental and Anatomically Accurate Computational Blast Injury Model", Journal of Neurotrauma, 29, 2352-2364 (2012). Link  pdf
7. M. Skotak, F. Wang, and N. Chandra, "An in-vitro model for SH-SY5Y neuroblastoma cell: Effect of strain and strain rate", Journal of Neuroscience Methods, 205, 159-168 (2012). Link  pdf
8. L. Gu, M.S. Chafi, S. Ganpule, and N. Chandra, "The influence of heterogeneous meninges on the brain mechanics under primary blast loading", Composites, Part B: Engineering, 43, 3160-3166 (2012). Link  pdf
9. S. Ganpule, L, Gu, A. Alai and N. Chandra, "Role of helmet in the mechanics of shock wave propagation under blast loading conditions", Computer methods in Biomechanics and Biomedical Engineering, 15, 1233-1244 (2011). Link  pdf
10. S. Ganpule, L. Gu, M.S. Chafi, and N. Chandra, "Dynamic response of brain subjected to blast loadings: Influence of frequency ranges", International Journal of Applied Mechanics 3, 803-823 (2011). Link  pdf
11. G. Cao and N. Chandra, "Evaluating the Biological Cell Properties Using Dynamic Indentation Method", Physical Review E, 81, 021924, 1-9, (2010). Link  pdf

Patents

1. N. Chandra, A. Holmberg, and R. Feng, "Controlling the shape of the shock wave profile in a blast facility", U.S. Provisional patent application no. 61542354, Oct. 3, 2011

Conference proceedings

1. M. Skotak, F. Wang and N. Chandra, "In vivo acute pathophysiology rodent model of primary blast injury", Journal of Neurotrauma, 29, A67-A68 (2012). The 30th Annual National Neurotrauma Symposium, July 22-25, 2012, Phoenix, AZ. Link  pdf
2. F. Wang, M. Skotak and N. Chandra, "An in vitro injury model for SH-SY5Y neuroblastoma cells: effect of strain and strain rate", Journal of Neurotrauma, 29, A77-A77 (2012). The 30th Annual National Neurotrauma Symposium, July 22-25, 2012, Phoenix, AZ. Link  pdf
3. N. Chandra and R. Gupta, "Shock loading-induced Traumatic Brain Injuries in animal models - experimental and computational studies". The 30th Annual National Neurotrauma Symposium, The 9th World Congress on Brain Injury International Brain Injury Association, March 21-25, 2012, Edinburgh, Scotland.  pdf
4. G. Cao, Y. Zhou, J. S. Lee, J. Y. Lim, N. Chandra, "Mechanical model of neuronal function loss", Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition (IMECE2010), November 12-18, 2010, Vancouver, British Columbia, Canada. Link  pdf
5. G. Cao, Y. Zhou, J. S. Lee, J. Y. Lim, N. Chandra, "Computational simulation of the deformation of neuronal cells", Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition (IMECE2010), November 12-18, 2010, Vancouver, British Columbia, Canada. Link  pdf
6. S. Ganpule, L. Gu, N. Chandra, " Modeling shock response of helmeted head using fluid structure interaction", 16th US National Congress of Theoretical and Applied Mechanics, June 27 - July 2, 2010, State College, PA.  pdf
7. M. Nienaber, J.S. Lee, R. Feng, J. Y. Lim, "Impulsive Pressurization of Neuronal Cells", 47th Annual Technical Meeting of Society of Engineering Science, October 3-6, 2010, Ames, IA.  pdf
8. J. S. Lee, M. Nienaber, R. Feng, J. Y. Lim, "A Kolsky Bar Technique for Impulsive Fluid Pressurization", BMES Annual Conference & Exposition, October 6-9, 2010, Austin, TX.  pdf
9. M. Nienaber, J.G. Vogeler, R. Feng, "A Kolsky Bar Technique for Impulsive Fluid Pressurization", SEM Annual Conference & Exposition, June 7-10, 2010, Indianapolis, IN. Link  pdf
10. S.G.M. Hossain, C.A. Nelson, E. Sogbesan, T. Boulet, M. Arnoult, L. Zhang, A. Holmberg, J. Hein, N. Kleinschmit, "Material Modeling and Development of a Realistic Dummy Head for Testing Blast Induced Traumatic Brain Injury", IV European Conference on Computational Mechanics, May 16-21, 2010, Palais des Congres, Paris, France. Paper  Presentation
11. G. Cao, N. Chandra, "Evaluating the Mechanical Behavior of a Cell Based on AFM indentation", 3rd International Conference on Mechanics of Biomaterials and Tissues, December 13-17, 2009, Clearwater Beach, FL.  pdf
12. G. Cao, N. Chandra, "Substrate effect on Dynamic Indentation Measurement of Biological Cell Properties", MRS Spring Meeting, April 13-17, 2009, San Francisco, CA.  pdf
13. S. Ganpule, L. Gu, G. Cao, N. Chandra, "The Effect of Shock Wave on a Human Head", Proceedings of the ASME 2009 International Mechanical Engineering Congress & Exposition (IMECE2009), November 13-19, 2009, Lake Buena Vista, FL. Link  pdf
14. S. Ganpule, L. Gu, G. Cao, N. Chandra, "Computational Modeling of Human Head Under Blast Loading", 10th US National Congress on Computational Mechanics, July 16-19, 2009, Columbus, OH.  pdf

Contact Us Namas Chandra, Ph. D., P.E. Elmer E. Koch Professor of Engineering Mechanics University of Nebraska–Lincoln Mechanical & Materials Engineering Work: W328.1 Nebraska Hall Lincoln, NE 68588-0526 Phone: (402) 472-8310 E-mail: nchandra2@unl.edu

Exciting Research Opportunities

Laboratory assistant

Immediate Opening (March 2013)

Trauma Mechanics Research Center at the University of Nebraska-Lincoln is looking for full-time/part-time laboratory assistants/technicians with instrumentations, trouble shooting, data collection and/or machining, building, testing experience. In our laboratory we are working on a number of real-world personal protection and defense related problems. Candidates with excellent academic record and relevant laboratory or industrial experience are preferred.

A degree in engineering or diploma with substantial experience is required. Passion for the job and professional dedication is a must. The opportunity comes with a great work experience and multi-disciplinary group activity.

Apply immediately by emailing your resume and a cover letter to Professor Namas Chandra.

Graduate students

Opening in Summer/Fall 2013

Trauma Mechanics Research Center at the University of Nebraska-Lincoln is looking for full time graduate students (Ph.D. preferred) to work on a number of real-world, defense related problems including:

• fundamental understanding of the mechanics of brain trauma
• blast and blunt impact experiments
• novel protection system for soldiers and athletes
• synergistic computer models based on field and laboratory measurements.

A B.S. or M.S. degree in mechanical engineering, biomedical engineering or allied field, with at least 3.5 GPA is a must. Passion for the job and professional dedication is a firm requirement. Selected candidates will be paid a return trip and stay in Lincoln for the direct experience and final selection. The opportunity comes with a great work experience in a multi-disciplinary group and we offer an attractive assistantship.

Apply immediately by emailing your resume and a cover letter to Professor Namas Chandra.