Research Projects

3 Dimensional Printing

Description

3DP is a mouldless rapid prototyping technique which employs ink jet printing technology for processing powder materials. It is a free-forming technology and ideal for high mix low volume production with low cost and short lead time. 3DP of titanium has great potential in biomedical sector where personalised dental or implant is required. 

Objective

One of the engineering requirements of an ideal implant is for the implant to have mechanical properties matching to that of the surrounding bones. Currently, most available implants have higher stiffness (elastic modulus) as compared to the bone. When an implant is stiffer than the bone, the implant would take the majority of the loaded stress. As the stress of the body now flows through the implant, the bone experienced reduced loading and therefore the bone will have its thickness decreased and mass lost. This phenomenon, termed stress shielding, will eventually result in early osteoporosis, bone fracture and implant loosening.

Approach

1) Computer aided design will be used to pre-design the implant to have graded porosity.
2) 3D printer will be used to fabricate the porous implant. Refinement of the printing process will be carried out to investigate the allowable processing windows for the printing accuracy, tolerance and dimensional size.
3) Modulus of the implant is controlled by the porosity of the implant. This is carried out by varying the implant design and fabrication process parameters, such as sintering process.

 

Contact PersonNai Mui Ling Sharon(mlnai@SIMTech.a-star.edu.sg)
Solution

Titanium is one of the most commonly used metallic materials for implant. In bulk form, it has low modulus as compared to other metallic biomaterials. As it is, titanium has the potential to be engineered to match the modulus to that of bone. 3D printing is a method that is able to produce complex customised products based on their computer representation. The porosity of the implant can be pre-designed, such that the implant has graded porosity structure similar to bones.

Benefits
  • The keys advantages of 3DP are:
  • Do not require expensive moulds which greatly reduce the cost for high mix low volume products
  • The ability to produce complex shape components including graded porosity structure
  • Can be designed to have customised component consisting of porosity and surface finishing, suitable for implant applications for individual patient requirements