December 13, 2018

NOVO Turns to Machining, Molding for Medical Device Prototyping

By Protolabs

Founded in 2004 in San Diego County, NOVO Engineering is a design engineering firm that specializes in product development. NOVO’s development process and engineering experience have helped some of the world’s most successful technical product companies, as well as startups and mid-market companies, accelerate development cycles and time to market.

NOVO recently tapped our injection molding and machining capabilities to prototype a new applicator for a glucose monitoring system. In our Q+A, we cover how digital manufacturing fits within NOVO’s design process and the challenges the company overcame during the development of this medical device.

glucose monitoring system
NOVO Engineering used a combination of injection molding and CNC machining to develop early stage prototypes of a glucose monitoring system. Pictured above is the final production design.
Can you start by sharing the product you designed and how it functions?

We came to Protolabs while we were designing and developing a single-use applicator for the sensor and base components of a continuous glucose monitoring system for patients with Type 1 and Type 2 diabetes. When applied to the body and triggered by the user, the applicator automatically inserts a sensor subcutaneously, makes the electrical connection, and adheres the transmitter base to the patient. NOVO’s role in this product development effort included the initial concept development, feasibility prototypes, and the design and development of early-phase prototypes.

What parts did Protolabs manufacture for NOVO?

Because our in-house machine shop was overloaded at the time, Protolabs manufactured all plastic components of our machined prototypes used for proof-of-concept and manufactured all injection-molded components of our disposable device used for engineering verification testing (EVT).

What manufacturing challenges did you encounter while developing the glucose monitoring device?

There were several development challenges that we overcame with Protolabs’ manufacturing services. We needed to machine several complex geometries for proof-of-concept models and functional prototypes. Protolabs’ fast lead times for machined parts were critical to keeping our project on schedule and facilitated multiple design iterations.

For our molded parts, we worked with Protolabs to supply a medical-grade thermoplastic that was not on their standard material list. The design also required different surface finishes on certain features, so we applied various mold polishes within a single tool. Some of the tooling incorporated features that could not be generated with conventional machining, so it was necessary to use a combination of EDM and CNC machining to fabricate the molds.

You supplied your own medical-grade material—tell us about it.

The application required that we use medical grade thermoplastics. The materials we chose were both cost-effective and offered good material properties. We also had to select materials with low friction coefficients because of the sliding interfaces in the design.

How many prototyping versions did you work through before finalizing design? Did the automated design analysis help during the process?

There were at least five major prototype revisions with progressively greater function and reliability. Successive generations also incorporated industrial design and usability enhancements driven by human factors studies performed by the client. Both the automated design analysis and applications engineers at Protolabs were invaluable in getting accurately molded parts in an expedited timeframe.

Why Protolabs? Can you provide any data on actual cost savings or time?

We chose Protolabs for its competitive pricing, extremely fast turnaround times, and high-quality prototype tooled parts. The low prices, capacity, and expedited delivery times allowed us to maximize the number of design iterations. To have come close to that level of turnaround time, we would have had to displace all the other client work in our shop and/or run second shifts. In our experience, Protolabs often provides better pricing and delivery than either local shops or other online suppliers for machining and molding.

What role will Protolabs play in your company’s future?

Protolabs has invested heavily in their processes and they work hard to keep their customers satisfied. Though we have in-house capabilities and other qualified suppliers, Protolabs will continue to be an important part of our supply chain for machined and injection-molded parts during development. The addition of 3D printing capabilities from Protolabs has been an added benefit for evaluating different materials and 3D printing processes for prototype parts.