Thinking outside the chip: Designing and developing microfluidics

Steve Green, head of design at Oxford Product Design, explores some lesser discussed challenges in the design and development of microfluidic devices for healthcare.

Broadly speaking, microfluidics involves the behaviour, manipulation, and control of fluids that are constrained within very small geometry, typically at the micrometre scale. In the medical industry, microfluidics has become an increasingly important tool for several applications.

One key advantage of microfluidics is the ability to handle very small amounts of biological material, such as blood or saliva. This can be especially useful for diagnostic testing to take small samples.

By enabling researchers and clinicians to handle and analyse small volumes of biological material with high precision and accuracy, microfluidics is helping to drive advances in diagnostics, drug discovery, and personalised medicine.

Within diagnostics, microfluidics is being widely used when developing point-of-care systems, which can be used to quickly detect diseases or conditions within a clinical setting. These devices can be designed to be portable, inexpensive per test, easy to use, and quick to result making them ideal for emergency situations. 

It is an exciting and rapidly evolving field with tremendous potential to revolutionise the way we approach healthcare, receiving lots of attention from the media, academia, and venture capitalists. Although there are devices starting to penetrate the market, the realisation of these benefits may not yet be reflective of the money and effort being put in.

An obvious challenge which attracts much of the effort and attention during development is of the microfluidic device (or ‘chip’) itself. The interplay between fluid dynamics, surface chemistry, and microfabrication techniques, as well as understanding the underlying physics and chemistry makes for an attention absorbing technical hurdle. Also, the requirement for reliable, reproducible, and scalable results requires careful balancing and optimisation of efforts throughout the design and development process.

However, the microfluidic ‘chip’ is only a small part of the larger system and integrating these devices with other components and requirements can be challenging.

Here are some aspects of microfluidic systems that fall ‘outside the chip’ that shouldn’t be ignored:

System Integration: In many cases, microfluidic systems must be integrated with external systems, such as pumps, valves, and sensors. 

Interfaces: Fluid flow is driven by pressure gradients. Designing fluidic connections and interfaces that are clean, reliable, leak-free, and easy to use can be a significant engineering challenge. 

Controls (sensing & feedback): To achieve closed-loop control over microfluidic systems, it is often necessary to incorporate sensors and feedback mechanisms. This can be challenging due to the small size of the system, which may require the development of specialised sensing technologies that can operate at the microscale.

Stability and robustness: Microfluidic systems can be sensitive to changes in environmental conditions, such as temperature, humidity, and vibration. Developing stable and robust systems requires careful design of components and materials, as well as advanced control algorithms.

Sample introduction: Introducing biological samples into microfluidic devices presents challenges such as sample preparation, handling, and storage; sample volume and concentration; contamination and cross-reactivity; and assay development and validation. These challenges must be carefully managed to ensure that microfluidic devices produce reliable and accurate results.

User interface and user experience: In a clinical or research setting, microfluidic devices must be easy to use and intuitive for end users. Developing user interfaces that are clear, concise, and provide relevant feedback can be a significant design challenge.

Approval & adoption: Although there are reasons to be positive about the systems becoming more open and efficient, it’s justifiably slow moving and risk adverse. Make it easier for everyone involved by understanding your market and planning your approvals pathway from the start.  

These are just some of the challenges involved and the complexity of this development landscape goes someway to explaining the gap between innovation and implementation of such devices in the field.

However, the potential benefits of microfluidics make the development journey a purposeful and impactful investment of time and energy so there is no doubt it’s the future. The question is how do we most efficiently and effectively bring such devices to market?

Strategy: Having a clear and well-communicated strategy is crucial to ensure that the device meets its intended application and requirements. It helps to identify the key challenges, resources, and milestones necessary for successful development. Remember that a strategy needs to be flexible and adaptable.

Collaboration: bringing together experts from different disciplines with complementary skills and knowledge is essential as it enables the integration of diverse perspectives, which can lead to more creative and innovative solutions to complex challenges.

In any one device development very few of these challenges are being solved for the first time. If start-ups, multinationals, service providers, suppliers and industry can find ways to work together more efficiently and effectively, then efforts within the field of microfluidics become more likely to pay off.

Oxford Product Design will be exhibiting at Med-Tech Innovation Expo on Stand C29 on 7-8 June at the NEC, Birmingham. Register for FREE at www.med-techexpo.com.