Program: Collaborative Research Program for Alumni (CRA)
Field: Mechanical and Manufacturing Engineering
Principal Investigator: Dr. Muslim Mahardika
Sending University: Universitas Gadjah Mada (UGM)
Japanese Co-Investigator: Asst. Prof. Dr. Norihisa MIKI
Japanese University: Keio University
Wearable artificial kidneys (WAK) have become popularly miniaturized separation and purification systems in dialysis treatment, because of their high efficiency, and one of their potential applications is in cleaning the blood of patients whose kidneys have failed. A WAK is smaller, less expensive and obviously more portable than the conventional hemodialysis systems widely used in hospitals, but its small size limits its inflow capacity and urea removal rate, as shown in Figure 2. A WAK consists of two main parts: a blood filter mainly dealing with the extraction of metabolic wastes such as urea, uric acid and creatinine from blood by using a clean dialysate, and a dialysate filter removing the metabolic wastes by various ways so that the dialysate can be reused.
In the previous work, Prof. Miki (Keio University) has successfully presented a multilayered microfilter for use as a dialyzer of a wearable artificial kidney. The microfilter device is assembled by alternately bonding chamber layers made of titanium etching. In this work we focus on fabrication of chamber layer using electropolishing technique.
Stainless steel 316L (SS 316L) material will be designed (Figure 3) and used as structural layer due to its high corrosion resistance, smoothness, and blood compatibility and also biocompatibility properties. However, SS 316L has also become one of the metal alloys that is difficult to be machined by conventional machining and also nonconventional process, because of force generated during the machining processes and problem in achieving smooth surface,. Surface etching and polishing are often required for shaping, machining and polishing of SS 316L and other metal alloys, especially as it requires polishing medical devices.
Many methods for chemical etching and electropolishing have been conducted. However, in most cases, chemical etching solutions contains of hazardous chemicals, such as hydrofluoric and sulfuric acids. Whilst electro polishing is considered as a safe and environment friendly process for polishing and machining of metallic materials since it uses non-toxic chemical solution. In addition, the process of removing material from the workpiece when immersed under the electrolyte requires small energy and can be conducted without heavy expensive equipment. Therefore, the fabrication of structural by using electropolishing method indicated its potential for use in manufacturing processes especially in the biomedical engineering research.
(Source: Application to CRA 2013)