Eastman and DD Studio demonstrate benefits of material supplier and designer collaboration.

From the initial design concept of a medical device to the manufacturing process, design engineers must rely on astute planning to help bring innovative products to market quickly and efficiently.

Bridging the information gap that can exist between designers and material suppliers through early and ongoing contact and collaboration is essential to streamline the development process and ensure the final product meets regulatory, functional and aesthetic requirements.

Through collaboration, resin supplier Eastman Chemical Company and design firm DD Studio share industry insight to enhance the overall prototyping and medical-device development process, showcasing the effectiveness of working together in all stages of product development.

Benefits of Collaboration

Design engineers should collaborate with material suppliers, OEMs and molders during the material selection process to identify the optimum material choice for a given application. Suppliers with a thorough understanding of materials can help identify the resin that possesses properties that will best meet the functional and aesthetic requirements of the end product.

For example, copolyesters are a versatile material specifically engineered to meet the performance demands of applications as varied as evacuated blood collection tubes to IV connectors, while achieving ideal visual attributes. These attributes include transparency, high gloss and low haze, as well as superior toughness and chemical resistance to lipids.

Designers can rely on suppliers to aid in assessing the processing attributes of a material, including its molding and cooling temperatures, flow, shrink characteristics and tooling requirements. This evaluation can optimize the production process to minimize manufacturing disruptions, decrease scrap and, ultimately, save time and money.

Additionally, material suppliers can provide critical advice regarding secondary operations, such as solvent and adhesive bonding, post-molding and cold forming, to ensure efficient production of quality, aesthetically pleasing parts.

Medical Design Collaboration

DD Studio, a California-based product design firm specializing in industrial design, engineering, prototype development and manufacturing, collaborated with the experts at Eastman starting in 2008 to advance strategic, human-centric innovations for a medical market that increasingly values design as a competitive advantage.

While DD Studio has worked with Eastman’s resins previously, the collaboration provided DD Studio the opportunity to explore the capabilities of a new material, Eastman Tritan copolyester.

At the same time, an inside look into DD Studio’s design process provided Eastman engineers insight into industry issues, helping to envision next-generation materials and work toward developing valuable and practical new solutions.

Through the exchange of design and material expertise, the teams worked together to develop a prototype to explore and showcase the capabilities of Eastman Tritan copolyester.

The knowledge gained during development was used in the collaboration on a wireless vital signs monitoring system. Tritan, a new-generation copolyester introduced to the medical market in 2009, provides design flexibility; ease of processing; outstanding lipid and chemical resistance; and added durability and toughness.

Material Testing

Specifying materials for prototype development requires an understanding by designers and material specifiers of required material properties for a given application. Materials are positioned by their capacities to meet a designated list of requirements, such as clarity, temperature threshold and impact strength, and each material, such as polycarbonate (PC), polyethylene terephthalate (PET) or copolyester, presents specific strengths that make one a better choice than alternatives, dependent on the application requirements.

To determine the uses and capabilities of Eastman Tritan copolyester, DD Studio conducted rigorous material tests. After more than a year of testing the drop impact, stress and chemical resistance of Tritan, DD Studio found the material exceeded all expectations.

Whereas many materials require product development teams to make compromises in material qualities, DD Studio discovered Tritan is the first of its kind to possess the characteristics required to specify it universally for applications ranging from IV system components and cannula tubes to mobile, wireless applications, satisfying the needs of all product development team members.

Prototype Design, Development

DD Studio and Eastman developed a three-dimensional double-dose cup prototype with Eastman Tritan copolyester that demonstrates its design flexibility and the depth and breadth of its capabilities.

Choosing to highlight the surface gloss, durability, clarity and variable wall thickness attributes, Eastman and DD Studio began prototype development. Composed of individual pieces that create a functional medical cup when assembled, the double-dose cup would supply a lasting function for users while encouraging playful interaction.

During design and development stages of the double-dose cup, DD Studio’s technical and design experts discovered a unique secondary operation of Eastman Tritan copolyester — cold swaging.

Cold swaging is a joining technique that involves bending and crimping a plastic part without the use of adhesives, chemicals or mechanical fasteners — creating a tight, smooth and continuous fit between two parts, and providing additional opportunities for designers and fabricators.

Sotera Wireless Vital Signs Monitoring Device

The cold swaging ability of Eastman Tritan copolyester also contributed to the material specification of Tritan in another collaboration between Eastman and DD Studio. The ViSi Mobile™ wireless, continuous vital signs monitoring system by Sotera Wireless Inc. incorporates the material’s design flexibility, chemical resistance and durability, and utilizes cold swaging for fit-and-press device assembly.

The system — composed of a wireless device that straps to a patient’s arm to monitor vital signs; a monitoring device to keep clinicians connected to patients’ information; and a charging station — was recently unveiled by Eastman and DD Studio.

Eastman supported the design exploration with its Innovation Lab, providing applied material science to meet the rigorous functional requirements of the device, such as being a small, user-friendly, chemical-resistant, easy-to-clean, durable and lightweight device. DD Studio relied on compatibility samples and testing results to specify GLS Versaflex OM 3060 TPE to seal the device housing, including speaker ports and microphone, from water and debris.

This process allowed Eastman to better understand materials that can adhere to an Eastman Tritan copolyester substrate while also providing experience in overmolding Tritan with elastomers.

Material properties and manufacturing considerations feed directly into developing holistic solutions for the medical industry. Through design collaboration, the healthcare industry benefits from collective knowledge on material and design properties. The double-dose cup and Sotera Wireless device by Eastman and DD Studio are examples of the value of design engineers and material suppliers working together through all product development stages to identify material solutions that help bring next-generation medical devices to the marketplace.

As the healthcare industry continues to demand safe, durable, reliable and user-friendly medical devices, ongoing strategic collaboration between design engineers and material suppliers can help meet and exceed these expectations.