Drug delivery devices such as autoinjectors, inhalers and surgical tools depend on absolute reliability to meet stringent medical trials. Each component must perform perfectly, often under complex mechanical conditions, and springs in particular as they drive their actuation mechanisms.
These seemingly simple components are fundamental to achieving consistent dosage delivery, patient safety and the zero-failure tolerance required in today’s stringent medical environments. In order to ensure complete long-term reliability, engineers need a clear understanding of how to integrate these springs into medical devices.
Medical springs are precision-engineered to deliver specific force profiles within tightly controlled tolerances. In drug delivery devices, they typically serve one of two main functions: energy storage and controlled release, or return-to-position mechanisms. Their job is to enable consistent actuation force over time and usage cycles, ensuring that whether it’s the first or the thousandth use, the device performs identically.
For instance, in autoinjectors, springs are used to drive needles and expel the medication at a controlled speed. In dry powder inhalers, they may be used to rotate dose counters or trigger medication release. In surgical instruments, torsion or compression springs help reset components or enable ergonomic actuation.
The design and selection of springs for these applications require precise understanding of mechanical properties, lifecycle behaviour and long-term material stability.
To meet the uncompromising standards of the pharmaceutical industry, spring design must factor in a number of key aspects.
Drug delivery devices are often exposed to varying environmental conditions (temperature, humidity, mechanical shock) and in some cases, repeated sterilisation cycles. Springs must maintain their mechanical integrity despite these factors.
Material surface finishing plays a vital role in preserving spring durability. For instance, passivation removes surface contaminants and improves corrosion resistance, whilst electropolishing can smooth micro-roughness to reduce particulate generation and extend fatigue life.
Such treatments are essential in devices where even microscopic particulates can lead to compliance failures during medical trials.
Springs not only need to perform in the final product but also survive the demands of the manufacturing and assembly processes. Design for Pharmaceutical Manufacture (DfPM) principles stress the importance of components that support low-complexity, high-speed assembly without deformation or performance loss.
Custom springs that are shaped and coiled to exact standards ensure they integrate seamlessly into automated assembly lines, reducing scrap rates and increasing manufacturing yield.
Medical springs play a vital role in ensuring consistent, reliable actuation across a wide range of drug delivery devices by delivering precisely calibrated force profiles within tightly controlled tolerances. Their ability to maintain performance over repeated usage cycles makes them indispensable to the success of autoinjectors, inhalers, and surgical tools.
At Advanex Medical, we understand the critical nature of spring components in medical devices. Our team supports OEMs and device designers from early-stage prototyping through to full-scale production. Using advanced forming techniques, in-line laser deburring and proprietary quality assurance protocols, we produce springs that perform and continue to do so reliably throughout the life of the device.
Whether you’re developing a next-generation autoinjector or improving a surgical tool’s lifecycle, precision-engineered springs are key to ensuring safe, consistent and dependable actuation. Download our guide below to find out more.