Jason Carey's Current Research Focus

1. Braided and other composites:

Braided composites are one of the oldest textile composite materials; however, their use in industrial applications is quite low. This is a result of the production process, often heterogeneous and inconsistent material properties, the little data available about complex loading behaviour, and proper modeling tools. Building on 20 years of work in the area, my group and I have made significant advances as a result of NSERC Discovery funding in advanced manufacturing of braided composites using green materials, the effect of yarn twist, and braidtruded rebar, as well as understanding and assessing their material behaviour and developing accurate models. We have expanded the use of classical laminate plate theory to additive polymer manufacturing. We have used digital image correlation techniques to assess braided composites behaviour. Progress has led to the development, or improvement, of analytical models to predict elastic constants that include closed and open mesh diamond unit cell configurations, trapezoidal unit cell for tapered and transitional regions of braid manufacturing, unit cell curvature effects, and mandrel diameter. Results have significantly improved existing work to predict elastic constants. Our regression-based models have made advances in simply predicting elastic constants compared to those found in the literature. Building on this work, we more recently determined the importance of accounting for changing braid angle and specimen dimensions to determine elastic properties; this work showed evidence of braid unit cell auxetic behaviour, which will impact the implementation of structural braid reinforcement and opens new areas of research for composites. Modeling and experimental work has expanded from Diamond to Regular and Hercules braided unit cells. Recent work on strand path and strand cross-section geometry using microCT imaging has confirmed the uneven nature of the repeating unit cell, challenging the axiom of a unit cell can represent a complete structure. This confirmed current production challenges and is forcing us the reassess predictive methods. Also, to increase the breadth of braids, this work has led to applied industrial projects and NSERC CRD funding; Sanjel uses our software. Our braid and composite material manufacturing and testing facilities are used for composites service contract work. My group is one of few working intensely in the area, nearly matching some of the early pioneering groups. His work has led to the current collaboration with Dr. Dolez.

2. Orthodontic research:

Measuring single root-tooth PDL F/D Behaviour, and Developing and Assessing Constitutive Relations of Its Behaviour: Project objectives are i) develop and refine a Quasi-linear Viscoelastic constitutive model for short-term force-displacement periodontal ligament behaviour during malocclusion based on rabbit results; ii) further verify the model applicability using porcine mandible single root teeth force-displacement experiments; and, iii) verify load-displacement PDL model predictions of the behaviour of embalmed human cadaver mandible single root teeth using the same approach as (ii).

PDL Adaptor Development for Orthodontic Simulator: Project objectives are to improve our in-vitro experimental equipments (OSIM, torsion and friction devices) by developing a PDL adaptor for single root-teeth based on previous experimental findings. Current focus will be on OSIM improvement.

Furthering Full Skull Finite Element Model for ME and Tooth Movement: Projects objectives are i) to improve the existing FEM model by integrating PDL and MS constitutive relations from projects 1(a) and 2(a) results, ii) verify results with rabbit and porcine experimental results, and iii) compare results with embalmed skull experimental work we did previously and literature results from previous work for full adolescent maxillary complex expansion.

Assessment of PDL Adaptor Effects on Archwire/Bracket Mechanics with OSIM: Project objectives are i) perform a preliminary evaluation of OSIM tooth PDL attachment using our standard OSIM testing protocol; ii) use an embalmed human skull with a suitable malocclusion and treat with archwire/bracket system, replicate test case in OSIM and compare in-situ and in-vitro results.

3. Biomedical Engineering:

This area remains a passion and demonstrates breadth of application of my expertise. Working with transdisciplinary teams of researchers, we have completed important work in muscle modeling to better appreciate the efficiency of muscular work, proper training protocols in sports activities; and detecting ice skating temporal events. We have advanced airway modeling processes, developed a guide and procedure for breast reduction resulting from breast cancer, and developed a surrogate mechanical neck for helmet testing wit the aim of minimizing concussions and reducing head impact trauma.

4. Clinical technology:

Upper arm amputees often reject their prosthetics; in the case of expensive, life altering myoelectric prosthetics, the numbers range in the 40-50%. The advancements of earlier work on developing an upper arm amputee myoelectric training tool to improve adoption through games-play and training has grown significantly through the creation of the BLINC lab and our collaboration with the Cleveland Clinic. The group holds an NIH grant (on which I am a collaborator). Our work creating feedback to amputees through their prosthetics using the kinesthetic illusion is ground breaking. The group's work has been to develop technology, model the vibratory input to the residual arm and prosthetic/residual arm interface, and to develop procedures to assess the kinesthetic illusion. We expect this work to lead to greater adoption of myoelectric prosthesis by amputees, increasing the quality of life and impact in society. This work has led to 6 journal and 12 conference publications. Our findings on the kinesthetic illusion was accepted in Science – Translational Medicine as a unique means of providing feedback; in the paper, blindfolded and ear-muffed patients replicate, through the principle of kinesthetic illusion, with their normal hand the motion of a robot hand that is transmitted through vibratory sensation to their amputated arm, which is truly extraordinary.

The scope of the project will include completing the development of the MTT as a research and training tool, and manufacturing a second portable device to allow take home and multiple site use. In order to decrease the cost of future MTT prototypes a custom signal conditioning board will be designed to replace the off-the-shelf EMG acquisition system. Additional features will be added to the MTT to improve its functionality including an improved simulator with a dynamic model to allow patients to virtually train activities of daily living prior to their actual prostheses fitting and an EMG controlled video game interface.

My general research interests are in the areas of composite and biological materials mechanics, biomedical engineering design, biomechanics of orthodontic treatment and orthodontic imaging, tissue mechanics and sports and injury biomechanics.

5. Engineering education:

Engineering education is a critical aspect of my current role of Vice Dean. This work has been vital in the current pandemic, moving our programs online and the lessons we learned must be shared widely. I have worked on establishing university wide graduate attributes that align with those of CEAB; processes for continual improvements and changing culture vis-à-vis program and course learning outcomes; developed transdisciplinary courses and a first year design course, establishing the validity of universal student ranking of instruction, and established and developed PhD communication requirements. This work led to receiving the 2020 APEGA Summit Award in Education Excellence and the 2020 University of Alverta’s Vargo (research in) Teaching Chair.