Uploaded May 2014 | Updated September 2026, 2 days ago
Materials Challenge: Implants
"I am Titanium"
For centuries, humans have been searching for materials to replace damaged or failed human tissue. These tissue replacements, or implants, have included everything from bits of shell hammered into the jaw to replace missing teeth to the metal hip and knee replacements we see today. There are many unique challenges in selecting materials for implants, as in addition to having properties similar to the failed biological component the implant must repair or replace, any material used must not be toxic to the human body. Titanium is a commonly used material in implants because it is strong, durable, and bonds with bone. It is not perfect, however, the high Young's modulus, or stiffness, of titanium can result in stress shielding -- where the implant bears more of the body's load than the surrounding bone, causing the bone tissue to weaken and fracture.
Our video will provide an introduction to implants by defining the term, giving a brief history of the development of implants, and giving some examples of the types of implants used today. We will then discuss the specific properties required of implants, including strength, durability and biocompatibility. We will then discuss titanium implants specifically -- the properties of titanium, what makes it work well for implants, as well as some of the challenges associated with the use of titanium and its alloys. We will discuss stress shielding in more detail, and demonstrate cold working -- a process by which the yield strength of metals can be increased without affecting the Young's modulus.
References:
1. Arsenjev, A. P.; Arsenjev, P. A.; Evdokimov, A. A.; Makaricheva, E. U.; Sheinin, M. J., "The processing of surgical implants from pure titanium," Biomedical Engineering Conference, 1996., Proceedings of the 1996 Fifteenth Southern , vol., no., pp.384,385, 29-31 Mar 1996 ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=493256&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D493256
2. C.N. Elias, J.H.C. Lima, R. Valiev, and M.A. Meyers. "Biomedical Uses of Titanium and its Alloys". JOM, March 2008. Pgs 46-49. http://www.meyersgroup.ucsd.edu/papers/journals/meyers%20316.pdf
3. M. Niinomi and M. Nakai, "Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone," International Journal of Biomaterials, vol. 2011, Article ID 836587, 10 pages, 2011. hindawi.com/journals/ijbm/2011/836587
4. Neailey, K., and Pond, R.C. (1982). Metal implants. Materials & Design, Volume 3, Issue 3, Pages 470-478. sciencedirect.com/science/article/pii/0261306982901133.
5. Springer Science+Business Media. (2011, July 26). Heavy metal: Titanium implant safety under scrutiny. ScienceDaily. Retrieved May 5, 2014 from sciencedaily.com/releases/2011/07/110725101257.htm
6. Slides from a Materials Science/Biomaterials Course; details processes, properties and uses of metallic biomaterials: http://www.bioen.utah.edu/faculty/pat/Courses/biomaterials2006/Metals%20and%20Applications%20in%20Orthopedics.pdf
7. How It's Made (YouTube clip): Titanium Dental Implants youtube.com/watch?v=S4j_GOYFoG8
All unoriginal images were unlicensed and accessed through Wikipedia.
Titanium by David Guetta ft. Sia
Materials Challenge: Implants
"I am Titanium"
For centuries, humans have been searching for materials to replace damaged or failed human tissue. These tissue replacements, or implants, have included everything from bits of shell hammered into the jaw to replace missing teeth to the metal hip and knee replacements we see today. There are many unique challenges in selecting materials for implants, as in addition to having properties similar to the failed biological component the implant must repair or replace, any material used must not be toxic to the human body. Titanium is a commonly used material in implants because it is strong, durable, and bonds with bone. It is not perfect, however, the high Young's modulus, or stiffness, of titanium can result in stress shielding -- where the implant bears more of the body's load than the surrounding bone, causing the bone tissue to weaken and fracture.
Our video will provide an introduction to implants by defining the term, giving a brief history of the development of implants, and giving some examples of the types of implants used today. We will then discuss the specific properties required of implants, including strength, durability and biocompatibility. We will then discuss titanium implants specifically -- the properties of titanium, what makes it work well for implants, as well as some of the challenges associated with the use of titanium and its alloys. We will discuss stress shielding in more detail, and demonstrate cold working -- a process by which the yield strength of metals can be increased without affecting the Young's modulus.
References:
1. Arsenjev, A. P.; Arsenjev, P. A.; Evdokimov, A. A.; Makaricheva, E. U.; Sheinin, M. J., "The processing of surgical implants from pure titanium," Biomedical Engineering Conference, 1996., Proceedings of the 1996 Fifteenth Southern , vol., no., pp.384,385, 29-31 Mar 1996 ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=493256&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D493256
2. C.N. Elias, J.H.C. Lima, R. Valiev, and M.A. Meyers. "Biomedical Uses of Titanium and its Alloys". JOM, March 2008. Pgs 46-49. http://www.meyersgroup.ucsd.edu/papers/journals/meyers%20316.pdf
3. M. Niinomi and M. Nakai, "Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone," International Journal of Biomaterials, vol. 2011, Article ID 836587, 10 pages, 2011. hindawi.com/journals/ijbm/2011/836587
4. Neailey, K., and Pond, R.C. (1982). Metal implants. Materials & Design, Volume 3, Issue 3, Pages 470-478. sciencedirect.com/science/article/pii/0261306982901133.
5. Springer Science+Business Media. (2011, July 26). Heavy metal: Titanium implant safety under scrutiny. ScienceDaily. Retrieved May 5, 2014 from sciencedaily.com/releases/2011/07/110725101257.htm
6. Slides from a Materials Science/Biomaterials Course; details processes, properties and uses of metallic biomaterials: http://www.bioen.utah.edu/faculty/pat/Courses/biomaterials2006/Metals%20and%20Applications%20in%20Orthopedics.pdf
7. How It's Made (YouTube clip): Titanium Dental Implants youtube.com/watch?v=S4j_GOYFoG8
All unoriginal images were unlicensed and accessed through Wikipedia.
Titanium by David Guetta ft. Sia

![Lithium Ion Batteries in Electric Vehicles
By Austin Anderson, Lewei He, Kiri Nicholson, and Brooke Noeska
Adoption of electric cars has been on the rise for the past decade due to the substantial advances that have been made by improvement of technology. The greatest challenges regarding electric cars are their batteries. Finding a balance between battery life, weight, rechargeability, and cost has proven to be a significant issue.
This video focuses on lithium-ion batteries used in electric vehicles. First, we provide a quick survey of electric vehicle designs. We then discuss chemistry, physics, and material science behind basic design of lithium-ion batteries. Next, we look at challenges that electric vehicles and the batteries face, which is the balance between adequate energy storage and weight of the battery.
How do we solve these challenges? The answer to this question lies within the material science paradigm triangle, which looks at property, processing, and structure. One key aspect in performance of the battery is the use of silicon versus graphite anodes, in which lithium ions are absorbed. Considering properties, graphite is more stable while silicon can absorb more ions, although they sometimes absorb too much and fail due to the mechanical stress. Considering processing, silicon films as thin as 20nm can absorb nearly the maximum amount of ions while limiting the amount of load the ions create. Finally, in a structural view, research has shown that small amount of tin in silicon anodes can greatly enhance capacity. Similarly, silicon-graphene anodes are another option with improvements in capacity and stability. In this perspective, the way to improve performance is clear: thinner silicon sheets with small amount of tin.
Lithium ion batteries hold a lot of advantages over other types of power sources. Compared to gasoline, vehicles produce less emission by using power that may be generated by renewable and nuclear energy. Compared to other batteries, lithium-ion provides high energy density by weight, relatively low amount of toxic and hazardous elements, and a good cycle durability.
The future of electric vehicles is immense, and with advancements in material science, lithium-ion batteries will likely continue to provide the energy that not only drives cars, but also drives the growth of the market of electric vehicles.
References:
Armand, M., & Tarascon, J. (2008). Building Better Batteries. Nature: International
Weekly Journal of Science. doi:10.1038/451652a (Kiri, 4)
Bonheur, K. (2016, November 09). Lithium ion battery: Advantages and disadvantages.
Retrieved April 13, 2017, from
http://www.versiondaily.com/lithium-ion-battery-advantages-disadvantages/
(Kiri 7)
Fuel Cells (n.d.). Retrieved April 29, 2017 from
http://www.iop.org/resources/topic/archive/fuel/ (Lewei)
Gordon-Bloomfield, N. (n.d.). Drive a Solar-Charged Electric Car, Save $263,000 On Fuel Over 50 Years? Retrieved May 06, 2017, from http://www.greencarreports.com/news/1072774_drive-a-solar-charged-electric-car-save-263000-on-fuel-over-50-years (Austin)
Is Lithium-ion the Ideal Battery? (n.d.). Retrieved April 13, 2017, from
http://batteryuniversity.com/learn/archive/is_lithium_ion_the_ideal_battery
(Kiri)
Johnson, D. (2016, March 31). Silicon and Graphene Combo Finally Achieve
Lithium-Ion Battery Greatness. Retrieved April 29, 2017, from http://spectrum.ieee.org/nanoclast/semiconductors/materials/potential-of-silicon-and-graphene-together-for-liion-electrodes-realized (Brooke)
Lithium-ion batteries: Capacity might be increased by six times. (2016, August 8).
Retrieved April 29, 2017, from https://phys.org/news/2016-08-lithium-ion-batteries-capacity.html (Brooke)
Nightingale, S. (2016, August 03). Next generation anode to improve lithium-ion
batteries. Retrieved April 29, 2017, from https://techxplore.com/news/2016-08-anode-lithium-ion-batteries.html (Brooke)
Patent US20110269021 - Lithium ion battery. (n.d.). Retrieved April 13, 2017, from
https://www.google.com/patents/US20110269021 (1, Kiri)
Poole, I. (n.d.). Lithium Ion Battery Advantages & Disadvantages. Retrieved April 13,
2017, from
http://www.radio-electronics.com/info/power-management/battery-technology/lithium-ion-battery-advantages-disadvantages.php (Kiri 5)
Schalkwijk, W. A., & Scrosati, B. (2002). Advances in lithium-ion batteries
[0-306-47508-1]. Retrieved April 13, 2017, from
https://books.google.com/books?hl=en&lr=&id=LxwRBwAAQBAJ&oi=fnd&pg=PA
2&dq=lithium ion
batteries&ots=iPe1E1imBy&sig=SWZFulm00zK0mR3dnmfZDxnitoA#v=onepage
&q=lithium%20ion%20batteries&f=false
Found online via Google Books, used first part of book that was available for free
(2, Kiri)
US Census Bureau. (2012, September 3). Industry Statistics. Retrieved April 29,
2017, from https://www.census.gov/econ/isp/sampler.php?naicscode=447&naicslevel=3 (Brooke)
Full formal citations, including media:
https://docs.google.com/document/d/1sCPeQ1gHOVPE0COEYim5HV6xPzWtWXbF5XOx9km1w-I/edit?usp=sharing Lithium Ion Batteries in Electric Vehicles](https://i.ytimg.com/vi/x4qzxTEeCWU/mqdefault.jpg)


