Thermoforming of Film‐Based Biomedical Microdevices

Abstract

For roughly ten years now, a new class of polymer micromoulding processes comes more and more into the focus both of the microtechnology and the biomedical engineering community. These processes can be subsumed under the term "microthermoforming". In microthermoforming, thin polymer films are heated to a softened, but still solid state and formed to thin-walled microdevices by three-dimensional stretching. The high material coherence during forming is in contrast to common polymer microreplication processes where the material is processed in a liquid or flowing state. It enables the preservation of premodifications of the film material. In this progress report, we review the still young state of the art of microthermoforming technology as well as its first applications. So far, the applications are mainly in the biomedical field. They benefit from the fact that thermoformed microdevices have unique properties resulting from their special, unusual morphology. The focus of this paper is on the impact of the new class of micromoulding processes and the processed film materials on the characteristics of the moulded microdevices and on their applications.

Microwell Scaffolds for the Extrahepatic Transplantation of Islets of Langerhans

“…Microwell scaffolds were fabricated from the PEOT/PBT thin films and electrospun meshes by micro back molding [31], a variant of microthermoforming, which involves shaping a heated polymer film by three-dimensional stretching into a negative mold using a backing material (Figure S1) [32]–[35]. The negative mold was produced by Lightmotif BV (Enschede, The Netherlands) out of a 350 µm thick stainless steel (AISI 304) foil.…”

Lab-on-a-chip devices: How to close and plug the lab?

“…In addition, roll-to-roll hot embossing and sealing methods have allowed more commercially-attractive solutions particularly for biological applications that require disposable chips [68]. Thermoplastics properties of polymers also enabled the use of the microthermoforming technology for the fabrication of complex 3D microfluidic channels having micro-or nano-structures [69][70][71]. Furthermore, Chen et al introduced the concept of ''Shrinky-Dink'' microfluidics as a fast prototyping alternative to above-mentioned techniques [72].…”

Estimation of the structure dependent performance of 3-D rapid prototyped membranes

“…These changes include for example generation of a micro-structured topology or flow profile engineering. Surface patterning of flat-sheet membranes has been performed using phase separation micro molding, [3][4][5][6] thermoforming [7] and curing in structured molds. [8] Multiple flat-sheet membranes can be combined and compacted into space-saving modules by using spacers between the single membrane sheets to improve fluid flow profiles.…”