Application of laser engineered net shaping (LENS) to manufacture porous and functionally graded structures for load bearing implants.
Fabrication of net shape load bearing implants with complex anatomical shapes to meet desired mechanical and biological performance is still a challenge. In this article, an overview of our research activities is discussed focusing on application of Laser Engineered Net Shaping (LENS) toward load bearing implants to increase in vivo life time. We have demonstrated that LENS can fabricate net shape, complex metallic implants with designed porosities up to 70 vol.% to reduce stress-shielding. The effective modulus of Ti, NiTi, and other alloys was tailored to suit the modulus of human cortical bone by introducing 12-42 vol.% porosity. In addition, laser processed porous NiTi alloy samples show a 2-4% recoverable strain, a potentially significant result for load bearing implants. To minimize the wear induced osteolysis, unitized structures with functionally graded Co-Cr-Mo coating on porous Ti6Al4V were also made using LENS, which showed high hardness with excellent bone cell-materials interactions. Finally, LENS is also being used to fabricate porous, net shape implants with a functional gradation in porosity characteristics.
W. M. Keck Biomedical Materials Research Lab, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA. amitband@wsu.edu
Amit
A
Bandyopadhyay
B V
BV
Krishna
Weichang
W
Xue
Susmita
S
Bose
D000497:Alloys / Q000737:chemistry; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry; D002616:Chemical Engineering / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D019245:Compressive Strength; D007834:Lasers; D008422:Materials Testing; D008954:Models, Biological; D016062:Porosity; D019736:Prostheses and Implants; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D016474:Weight-Bearing
D000497:Alloys; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D014025:Titanium