THE MENU

Five families of materials

There is no perfect material. Each one trades how quickly you can make a chip against how well it works and how cheaply it can be made in volume.

Choose the material for the job: prototype, experiment or product.

GLASS AND SILICON

Where it all started

💎

🧪

Glass

Clear, inert, rigid and solvent-proof. Wet etching with hydrofluoric acid gives rounded channels

⚙️

Silicon

Etched with chip-industry tools into precise, deep, straight-walled channels, but opaque to visible light

💰

The catch

Cleanroom processes make them slow and expensive to prototype

Glass and silicon still win when chemistry, heat or precision demand it.

PDMS

The research lab's favourite

🧊

What it is Polydimethylsiloxane, a silicone rubber (often Sylgard 184, mixed 10:1 with curing agent)

Strengths Cheap, clear, flexible, easy to mould and bond, permeable to oxygen and CO₂

Weaknesses Absorbs small hydrophobic molecules, swells in many solvents, lets water evaporate

Best for Fast prototypes and cell culture, including most organ chips

PDMS made microfluidics easy, but its absorption can distort drug experiments.

THERMOPLASTICS

What products are made of

🏭

🪟

PMMA (acrylic)

Clear, cheap, easy to laser-cut and mill

🔬

COC / COP

Very clear, low absorption, low autofluorescence: ideal for diagnostics

🧫

Polystyrene

The standard plastic of cell-culture dishes and plates

Thermoplastics soften with heat, so they can be moulded by the million.

PAPER AND BEYOND

Cheap, simple and surprising

Paper wicks liquid with no pump and can be patterned with wax, so a test can cost cents. Hydrogels, 3D-printing resins and soft thermoplastic elastomers are newer options, each with its own trade-offs.

Every material is a trade-off between lab speed and factory scale.

UNIT 6 STUDY COMPLETE

🧱

Ready for the Fab Challenge?

You've compared the main chip materials and know why research loves PDMS while products use plastic.