Microthermoforming
Microthermoforming is the process of shaping very small plastic parts made from thermoplastic films or plates. The shape of these tiny parts, or microstructures, provides their technical function.
It is a secondary forming process, meaning the polymer is heated and softened but still solid when formed. This is different from other microfabrication methods like microinjection molding or hot embossing, where the material is melted during forming.
Molds for microthermoforming can be made from metal, silicon, or glass and are created using methods such as micromachining, lithography with electroplating (the LIGA approach), or wet and dry etching.
Researchers at institutes like KIT have used high-pressure thermoforming to make film microchips for capillary electrophoresis and for three-dimensional cell culture. In this setup, a heated plastic film is formed in a female mold in a single stage, often with air supplied through holes in the heating plate.
In lab settings, very thin thermoplastic films (about 20–100 micrometers) made from materials like polycaprolactone can be formed into micromold cavities using pressures up to 5 MPa.
The idea of microthermoforming appeared in the late 1990s. Notable early examples include dome-shaped microstructures for electrical membrane switches (1993) and corrugated microstructures for electrostatic actuators (1999). Sometimes a softer counter tool, such as an elastomer, helps shape the material. A rubber-assisted hot embossing approach was explored at Georgia Tech in 2006.
One key advantage of microthermoforming is that the material’s surface and bulk properties can stay intact after forming, allowing further modification and functionalization. This enables highly detailed micro- and nano-patterns on three-dimensionally formed films, including patterns on hard-to-reach side walls.
Thermoformed microparts can have useful properties like high flexibility, very light weight, low thermal resistance, and low background light or fluorescence. They are especially suited for microfluidic structures, which can include free-standing channels and reservoirs with very thin walls.
Because properties from the original film can be preserved, microthermoformed parts can be designed with tailored surfaces and internal features, such as pores, cell-adhesion patterns, surface textures, and integrated electrodes.
Future applications for microthermoforming are expected to grow across many fields as the technology advances.
This page was last edited on 2 February 2026, at 05:16 (CET).