Principal investigator: Mary Frecker, Todd Palmer, Eric Pauli

University: The Pennsylvania State University

Industry partners: Actuated Medical

Additive manufacturing (AM) is moving well beyond its early use as a tool for rapid prototyping; today, it’s used as a viable alternative for commercial manufacturing. AM offers the advantages of fabricating near net-shape components and customizing designs. Metal-based AM is a major research focus at Penn State University (PSU), and Pennsylvania-based Actuated Medical, Inc. (AMI) is rapidly developing their own AM capabilities to improve their competitiveness. In this project, PSU will provide AMI with a competitive technological edge by developing an innovative AM process, specifically targeted at advancing AMI’s core business in developing and manufacturing medical devices.

The project aims to develop a new AM process for functionally graded structures to enable breakthroughs in medical device technologies. Nickel-titanium alloy (NiTi) will be used, a biocompatible material that is currently used in other implantable medical devices. The technological breakthrough will be the ability to print NiTi parts with tailorable, non-homogeneous composition. The flow rates of nickel and titanium elemental powders are controlled in real time during fabrication using a direct energy deposition (DED) process. By varying the material composition and therefore the mechanical properties, we can exploit the superelastic property of NiTi in localized areas where large compliance is needed.

The new DED process development is accompanied by modeling and design optimization efforts targeted at a compelling clinical application: a functionally graded endoscopic stent for gastrointestinal procedures where drastically improved functionality is needed. A finite element model will quantify the device performance in terms of device geometry, functional grading, and mechanical properties as defined by the AM process. The project will culminate with printing scaled, functionally graded NiTi stent prototypes with localized superleasticity, and supporting the development of AMI’s new advanced manufacturing center which will bring medical devices with significant commercial and clinical potential to market.