Electropolishing of Nitinol Stents in Aqueous, Acid-Free Solutions

Details

• Personal Author:
  Inman M
• Description:
  1) How the Research adds to the Understanding of the Area Investigated: Faraday Technology proposed to demonstrate the feasibility of an innovative stent manufacturing process with the overall aim of addressing technological innovation in the U.S. manufacturing economy consistent with Executive Order "Encouraging Innovation in Manufacturing". Currently, all stents manufactured must undergo an electropolishing process that is commonly done in high concentration acid mixtures of sulfuric/phosphoric/hydrofluoric acid. The proposed process uses simple aqueous pH neutral electrolytes, eliminating process control difficulties and high reject rates (up to 40-50%) associated with current practice, reducing environmental and OSHA challenges, and therefore reduce cost and improving reproducibility. Initial commercialization is envisioned to occur via the replacement of the current electropolishing process with the acid free FARADAYIC(R), ElectroPolishing process. 2) Technical Effectiveness and Economic Feasibility: In the Phase I program, three different bench scale processing apparatus were designed/built for polarization/ flat coupon studies, for straight wire processing studies, and for loop clip processing studies. The FARADAYIC(R) ElectroPolishing Process was tuned to achieve surface roughness (Ra) values as low as 0.16 um using a salt solution consisting of 25 g/L KNO3 and 150 g/L Na2SO4 at an as-mixed pH of 5.88 when processing and 1" x 1" Nitinol coupons. The industrial benchmark for Ra is less than 0.2 um, and based on the results enclosed herein we anticipate lower values will be obtained with further development. Nitinol wires and loop clips provided by industrial partners were polished and showed the potential to achieve the desired finish required by the medical industry. This program demonstrated a non-toxic aqueous pH neutral electrolyte that is simpler to control and more environmentally friendly as compared to the concentrated sulfuric acid/phosphoric acid electrolyte used by the current state-of-the-art electropolishing technology. An a-scale high-throughput stent finishing apparatus was designed within the Phase I program and will be built at the onset of the Phase II program. Faraday installed onsite a high-throughput reel-to-reel strand electropolishing system designed by a commercial client for processing straight wire. Through commercial contributions, the system will be retrofitted to allow streamline processing medical device wires. Faraday compiling a manufacturing process flow and economic assessment. 3) How the Project Benefits the Public: This project meets the NIH mission by developing an innovative stent manufacturing process with the overall aim of addressing technological innovation in the U.S. manufacturing economy consistent with Executive Order "Encouraging Innovation in Manufacturing". This technology will enable a rapid, high yield, cost-effective manufacturing process for Nitinol stents, and will be compatible with stents and other medical devices fabricated from a wide variety of materials. Stents represent one of the fastest growing segments of the medical device market. From their introduction in 1990, the stent market has grown to over $5 billion in 2011. [Description provided by NIOSH]
• Subjects:
  Health Care Facilities Workforce And Services Manufacturing And Industrial Facilities Occupational Health Safety
• Keywords:
  Electrochemistry Electrolytes Electrolytic Refining Equipment Design Manufacturing Medical Equipment
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-34
• NIOSHTIC Number:
  nn:20054996
• NTIS Accession Number:
  PB2019-100817
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R43-OH-010391, 2014 Jun; :1-34
• Contact Point Address:
  Faraday Technology, Inc., 315 Huls Drive, Clayton, OH 45315
• Federal Fiscal Year:
  2014
• Performing Organization:
  Faraday Technology, Inc., Clayton, Ohio
• Peer Reviewed:
  False
• Start Date:
  20130901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20140831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1ac8b4f6b932c5179000df45dd0501e359e30dc942a61acb24f03355c5ef197692a25bf715e54140debe042b7fbd5f39c627409cd115bf9809da005ba9ddc385
• Download URL:
  https://stacks.cdc.gov/view/cdc/218830/cdc_218830_DS1.pdf
• File Type:
  [PDF - 1.40 MB ]