The workhorse of microfluidics and optical assemblies: 92 % light transmission, excellent machinability, and three bonding routes we run in-house. The constraint is thermal and chemical — not mechanical. Below is what acrylic will and will not do at tolerance.
Cell-cast sheet values at 23 °C / 50 % RH. Extruded sheet is 3–8 % lower in transmission and carries more internal stress — the difference shows up after machining and bonding.
| Property | Value | Why it matters for machining |
|---|---|---|
| Light transmission | 92 % at 3 mm, 88 % at 10 mm | Thicker sections lose transmission — specify optical grade and polish faces for imaging |
| Refractive index | 1.49 | Baseline for light-guide and lens design; unmatched to water (1.33) at the channel wall |
| Glass transition | 105 °C | Annealing at 80 °C is safe; exceeding 90 °C on a stressed part re-opens crazes |
| Continuous service temperature | 65–80 °C | Rules out autoclave and most in-line sterilisation — use PSU or PEEK instead |
| Tensile strength | ~72 MPa | Ample for manifolds and housings; brittle failure at notches, so radius everything |
| Flexural modulus | ~3.2 GPa | Stiff enough for 0.5 mm walls at chip scale |
| Coefficient of thermal expansion | ~70 µm/m·K | Seven times steel — a bonded acrylic-to-metal assembly needs compliant adhesive |
| Water absorption | 0.3 % / 24 h | Enough to move a 100 mm part by ~0.1 mm when humidity swings; condition before final measure |
| Chemical resistance | Good, with exceptions | Dissolved by ketones, esters, chlorinated solvents; crazes under stress in ethanol and IPA |
| Bonding | Solvent, thermal, adhesive | Only thermoplastic in this group with a true capillary solvent bond at room temperature |
| Cost index | 1.0 (baseline) | Cheapest of the engineering grades — prototype iterations stay affordable |
Optical grade, low internal stress, best polishing response and reliable solvent bonding. Our default for microfluidic chips, flow cells and optical windows.
Tighter thickness tolerance and lower cost, at the price of residual stress that appears as haze or bow after machining. Specify only when flatness is not critical.
For turned parts, cuvettes and light guides. Cast rod machines cleaner than extruded; tube is available in optical grade for flow-through cells.
Low haze (< 0.5 %), high transmission and no visible inclusions. Required for imaging channels, lenses and light-guide plates.
Toughened acrylic that resists edge chipping during handling, at the cost of a slight yellow tint. Used for housings rather than optical parts.
Black, white and opacified grades for light isolation between channels; UV-blocking grades for fluorescent assays where excitation bleed is a problem.
Single- and multi-layer devices for PCR, immunoassay and organ-on-chip. Solvent or thermal bonding, optical detection through the chip face.
Absorbance and fluorescence cells with polished optical windows, bonded inlet/outlet ports and defined path length.
Edge-lit plates and light pipes where transmission and surface polish drive the design; laser-cut edges can be flame-polished in one pass.
Bonded acrylic manifolds for low-pressure fluid routing, typically with stainless inserts for threaded ports.
Machine guards, sensor windows and display covers requiring optical clarity and impact resistance at room temperature.
Cheap, fast and bondable — the grade we use to prove a channel geometry before committing to COC/COP tooling.
When acrylic is not enough: heat, fluorescence background or impact strength usually drives the move.
Send the layer stack and the channel drawing. We will recommend solvent, thermal or adhesive bonding and quote the bonded assembly, not just the plates.
