Microfluidics, or lab-on-chip devices, are dealing with the precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter scale. These devices integrate one or several functions into a single chip. Microfluidics is a broader term that also describes mechanical flow control devices, including pumps and valves as well as sensors such as flow meters and viscometers. In the case of micro total analysis systems (µTAS), an entire sequence of lab processes is integrated into a single chip that performs a full chemical analysis. The term "lab-on-a-chip" generally describes the scaling of single or multiple lab processes down to chip format.

Hot Embossing
Hot Embossing is a very versatile replication method which uses high pressure and elevated temperature to transfer the structures from the master into the polymer.  It addresses a wide range of applications, from polymer-based lab-on-chip systems, where imprinting is done on thick polymers substrates to the fabrication of sub 50 nm features for bio-sensing or data recording applications, where imprinting is required.

EV Group's Hot Embossing Systems provide the best capabilities for large area imprinting applications. The systems are configured with a universal embossing chamber with top and bottom side heaters, offering high-vacuum and high-contact force capabilities to imprint spin-on polymers as well as polymer substrates.

Individual process steps featured by EV Group:

  • Working stamp fabrication
  • First print into spin on polymers
  • First print into polymer sheets
  • Aligned imprint into spin on polymers
  • Aligned imprint into polymer sheets
  • Double side aligned imprint into polymers
  • Automated de-embossing

Please see our related products EVG Hot Embossing Systems and EVG®770 Automated NIL Stepper for detailed information.

Conventional template fabrication methods include mechanical micromachining, laser micromachining and lithographic methods (LIGA, UV-LIGA). EV Group offers the possibility to use soft working stamps materials for hot embossing which exhibits multiple benefits over hard stamps as described below:

  • Soft working stamps can be fabricated at low cost, requiring only one precious master to start from
  • Rapid fabrication process compared to PDMS stamp technology
  • Rapid prototyping possible from lithography masters compared to LIGA processing for µm scale features
  • Soft working stamp can be used multiple times for hot embossing, thus stamps are multiplied
  • Soft working stamps do not require compliant layers as they are soft by their nature so that large area replication can be easily achieved
  • Soft stamps are fully compatible with optical alignment through their transparency (aligned HE from stamp to substrate compared to opaque master)
  • Soft stamps can replicate high resolution features for bio sensing applications (< 50 nm) as well as micro fluidic channels (several 100 µm)

Please see our related products EVG Nanoimprint Lithography Systems (UV-NIL, µCP) for detailed information.


SEM Image of 200 µm hot embossed micro fluidic channels.
Source IMI-NRC.

SEM Image of 20 µm hot embossed micro fluidic channels utilizing polymeric stamps (height 180 µm). Source IMI-NCR.

SEM Image of 50 nm and
100 nm hot embossed meander structures utilizing polymeric stamps. Source EVG.

SEM Image of 50 nm hot embossed liness utilizing polymeric stamps. Source EVG.