Micromachined surgical and bioimplant components
Using micrometal injection molding and photolithographic techniques, a supplier manufactures parts for surgical and bioimplantation applications from 17-4 PH steel alloy, 300-series stainless steel, F-75 alloy, and Grade 5 titanium. The company makes complex components, including ones for endoscopic devices, with feature dimensions less than 0.030 in., tolerances of ±0.3%, and surface finishes less than 10 µin. The manufacturer has also developed a lithographic-based microcasting technology for mass-producing metal alloy and ceramic microcomponents with feature sizes in the range of 0.001 to 0.003 in. A proprietary technology that relies on the use of high-resolution lithographic tooling, microcasting merges existing photolithographic methods with long-established powder metallurgical processes.
Advanced Powder Products Inc.
Tight-tolerance medical components
Specializing in the precision machining of components using an array of engineering plastics, a supplier to the medical device industry provides prototyping services as well as small- and large-volume production runs. To produce parts from PTFE, PEEK, PA, PE, ETFE, and other materials, the company employs a range of turning centers, including the Sigma 8, which can machine components to within tolerances of 1 µm. Because PTFE components are subject to expansion at elevated temperatures, making it difficult to hold tolerances to ±0.0005 in., the company maintains a temperature-controlled environment for its Tornos turning machines. In addition, the contractor has developed its own statistical process control (SPC) system for controlling these machines. This SPC system enables operators at the ISO 9001:2000–certified and AS9100-accredited company to monitor all part dimensions and characteristics in real time.
Micrometal injection molding
Providing sharp feature replication, good surface finishes, tight tolerances, and thin walls, micrometal injection molding (micro MIM) utilizes the shape-making capability of plastic molding and applies it using micrometal powders. This process results in high and uniform density, strength, and shape complexity, including undercuts and threads. While relying on conventional metal-injection-molding feedstock powders that produce minimum features and wall thicknesses of 0.015 to 0.020 in., micro MIM uses a finer grade so that the powders can fill tiny spaces and wall thicknesses down to 0.001 in. The product-handling and sintering process following micro MIM utilizes small end-of-arm tooling, automation, and nesting fixtures, resulting in the accurate and repeatable handling of delicate miniature parts.
Micro Engineering Solutions
Charlton City, MA
A contractor uses electroforming to mass-produce miniature NiColoy components such as tubes, bellows, optical housings and shields, microfluidic molds, and MEMS devices. Producing features ranging in size from several millimeters to a few micrometers, electroforming—in conjunction with precision machining, photolithography, and etching—involves plating a layer of metal onto a mandrel. When the mandrel is removed, the electroformed component remains. For use in microstent systems, the company’s electroformed seamless alloy tubing features an
inner diameter of 125 µm, an outer diameter of 150 µm, and a length of
635 µm. Because it is strong, the alloy ensures tight tolerances and the physical integrity of thin-wall components. The supplier also employs other metals, such as gold, copper, and nickel, and provides highly reflective, textured, matte, or light-absorbing finishes.
Parts for implantable applications
Expanding its capabilities to include medical micromolding, a contractor focuses on the manufacture of components for implantable devices. Using virgin resins that do not degrade, the company’s micromolding process delivers yields of 10,000 parts or 10,000 shots/lb minimum, yielding 0.003-cu in. parts or smaller that weigh 0.045 g or less. Utilizing in-house tooling capabilities, the company offers R&D services for unique applications and maintains a laboratory environment for expediting the transition from development to production. Complex part geometries and repeatability can be attained for components made from a range of materials, including PEEK, Ultem, bioresorbable materials, and other engineered resins.