Additive Manufacturing and Bioprinting
Lead Faculty: Dr. Jianzhi Li
Group Members: Anil Srivastava, Miguel Gonzalez, Andy Tsin, Dae Kim, Ben Xu
Projects:
1. Selective Laser Alloying: A innovative way of printing cermet with super high melting temperature, at a low process temperature based on elemental metal powder (CP Ti and B powders)
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Previous work: Process Modelling and Thermal Models and Experiment Verification
The concept of selective laser alloying to print 3D parts directly from elemental powders was first develop in this work. An investigation of the governing thermal models of the process was further conducted by this group. Considering the effects of exothermic reaction between Ti and B during the alloying process, thermal models with three group of parame ters were developed to predict the phenomena induced in the selective laser alloying process. To validate these models, a series of experiments, with different molar ratios between Ti and B, were conducted on Renishaw AM250 using premixed elemental Ti and B powders. The experimental validated the SLA concept and the results matched consistently with the models’ predictions, which validated the models.
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Yingbin Hu, Jianzhi Li, “Selective Laser Alloying of Elemental Titanium and Boron Powder: Thermal Models and Experiment Verification” Journal of Materials Processing Technology, 249 (2017) 426–432
- Current work: Multiscale process modeling and thermal and fluid dynamics and SLA
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2. Selective laser melting of mechanical alloyed metastable alloys (Al5Fe2 Powder) Selective Laser Melting (SLM), an Additive Manufacturing (AM) technology, enables the production of complex structured metal products. As high-strength lightweight materials, Aluminum alloys can be processed in SLM with high energy consumption and poor finish due to quick heat dissipation. Previous investigations reported high laser powers (300 W) and slow scanning speeds (500 mm/s) to process aluminum alloys under SLM. This research investigated the SLM processing of Al-Fe alloy by utilizing metastable Al5Fe2 powder system produced by mechanical alloying. Metastable systems are thermodynamically activated with internal energy that can generate an energy shortcut when processing under SLM. The optimum laser power, scan speeds and scan distances were investigated by test series experiments. Results indicate that metastable Al5Fe2 alloy can be processed and stabilized under a 200 W laser scanning and a relative high scanning speed of 1000 mm/s, therefore it is concluded that the internal energy of metastable powder contributes in reducing laser energy for SLM process for Al alloys.
3. Selective laser re-melting on inclined surfaces for surface roughness optimization of additive manufactured 316L stainless steel parts.
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4. Funding: ARO W911NF-14-1-0083, amount $488,000 Cooperative Funding (Renishaw): $211,432 (2015). Private funding $15,000 (2017). PUF: $130,000
Current Research in Bioprinting for Disease and Drug study
The UTRGV Biomedical Research group performs collaborative multidisciplinary research projects in the field of bio and medical device manufacturing. Currently two research projects are conducted by the research group.
1. Engineering the 3D Human Retina models
- Currently the team (Li, Tsin, one undergraduate student and one graduate student) is attempting to utilize a ultra-short laser bio printing system to develop the 3-D human retina organoid system that mimics the physiological and morphological features of the in vivo biology, consists of the major retina cell types with appropriate lamination and synaptic organization, and represents their biological functions and interplay.
- The ultimate goal is to use the printed retina to support future research in modeling and treating retinal disease, or testing and developing drug (i.e., high content screening) therapies.
2. Engineered Skin for Carcinogenesis Study:
- In this project, the team plans to grow skin cells and assembly them in to a structure that replicates the natural structure of the skin
- The longer term objectives of this project to 1) study the manufacturing science involved in appropriate bio printing process, and 2) develop engineered skin which allow school of medicine to study proliferation mechanism involved in keratinocyte.
