Manufacturing Microfluidic Glass Consumables

Micronit's foundry is known for its manufacturing capabilities on microfluidic glass consumables. Over 25 years, Micronit has built up a strong track record in developing and manufacturing microfluidic glass consumables for life science and health applications. In this article we can show you the tip of the iceberg in how microfluidic components are being made. 

Benefits of Glass Consumables – from a Manufacturer perspective

The manufacturing process of microfluidic consumables involves a wide range of conditions, including exposure to high temperatures, corrosive chemicals, and water. Glass as a substrate material is ideal for use in these environments for its chemical pureness, thermal shock resistance, and high mechanical stability. Glass is also an excellent material for the integration of electrical and sensing functions for its dielectric properties, high seal resistance, and absence of auto-fluorescence.

Fabrication methods of Microfluidic Glass Consumables

The use of glass for microsystems is a good option if the application needs excellent optical transparency combined with chemical inertness and extreme flatness. For glass parts and components a very precise and smooth micro- and nanostructures can be realized. Structuring of glass is mostly done by etching and laser drilling. There are also new methods for developing glass consumables, like 3D printing or molding glass components, but these methods are not suitable for professional set-ups or for upscaling in larger volumes.

Types of Glass that are used for Microfluidic Consumables

At Micronit the most used types of glass are Borosilicate glass (e.g. D263®, D263Bio®, Borofloat®, MEMpax®) and Fused silica. We also have experience with other types, options can always be discussed. 

·         Thickness: 0.1mm-2mm 

·         Thermal resistance: up to 450 °C 

·         Chemical inertness: high resistance to water, acids, alkalis, and organic substances 

·         Surface roughness: optical quality (≤ 1nm RMS) 

·         Autofluorescence: very low 

·         Refractive index: n = 1.5-1.9

Best Practices for your Design for Manufacturing process

As a leading foundry of microfluidic consumables, we can also help you with the design for manufacturing (DFM) process. Understanding design rules and manufacturing processes is crucial to optimize costs and efficiency. Key considerations include:

• In production we use standard-size sheets of glass with a usable surface of 140x140mm. The smaller the chip size, the more chips will fit on a substrate, therefore, the lower the costs per chip. Combining a small glass chip with a large cartridge or polymer microfluidic circuit board helps to make an easy-to-handle but cost-effective solution. 
• Aspect ratio is a crucial factor for costs. Aspect ratio is the relation between feature width and height. Small features that are combined with large depths are in general more complicated to manufacture than features with lower aspect ratios.  
• Keep your chip layout simple. Often it is the most cost-effective to keep the chip itself simple and add complexity to external hardware. 
• Limit the amount of different channel heights in a design. In glass manufacturing, each etch depth needs a separate etching step. 
• Consider a scenario in which your chip is re-used. Glass chips can easily survive thorough cleaning, so make use of this advantage! Whether it is by performing the same test multiple times or creating a versatile chip that could be used in different test settings. 
• A sideconnect microfluidic system takes away the need for separately manufactured inlet holes at the top of the chip. This saves a processing step and helps to reduce the chip size. 

Getting started

Are you working on a glass microfluidic device? Or would you like to discuss the best type of material for your project? Please, feel free to contact us directly. Our Sales and R&D teams will be happy to assist you!