Flexdym Polymer Starter Pack - alternative to PDMS
Rated 3.5/5 based on 11 customer reviews

Flexdym Polymer Starter Pack - alternative to PDMS

Try our brand new biocompatible polymer with this ready-to-fabricate start pack! The Flexdym is a great alternative to PDMS: self-sealing, resistant, cost-effective and biocompatible, it will greatly ease your work when fabricating chips. Contains 10 sheets of 15 x 15 cm Flexdym polymer.
Available within 1 week
Try our brand new biocompatible polymer with this ready-to-fabricate start pack! The Flexdym is a great alternative to PDMS: self-sealing, resistant, cost-effective and biocompatible, it will greatly ease your work when fabricating chips. Contains 10 sheets of 15 x 15 cm Flexdym polymer.

In this kit, you will be able to try the Flexdym with 10 sheets of 15 x 15 cm as an alternative to PDMS for your chip microfabrication. Different thicknesses are available upon request: 1.3 mm, 0.8 mm and 0.2 mm.


The Flexdym polymer is a real breakthrough for microfluidics

Features & Benefits

The Flexdym is a new polymer which gathers the advantages of PDMS without its drawbacks:

  • Biocompatible (ISO 10993-5 & UPS Class VI)
  • Self-sealing at ambient temperature: no need to use plasma bonding or high temperatures, you can then add biomaterials prior assembly
  • Cost-effective
  • Compatible for optical assays: low fluorescence, optically clear
  • No absorption, permeable to gas and not to liquid
  • Resistant to tearing: Unlike PDMS, it will not tear apart when you manipulate it

Effective integration, cellular and bio-reagents 

The high sealing performances of the Flexdym enable the integration of cells, proteins and others enzymes biomaterials prior to assembly. With a fabrication process that doesn’t involve plasma, vacuum or high-temperature, we can ensure that biological agents remain viable and functional in your device.

Fast microfabrication

  • Molding with a hot-embossing system
  • Low pressure: below 1 bar
  • No vacuum needed
  • Easy unmolding
  • Full operation takes less than a minute
  • Extremely low viscosity for rapid thermal molding with filling rates up to 100-1000 times greater than classical rigid thermoplastics (COC, PS, PMMA,…)


Flexdym is an alternative to any other chip material in the classical applications of microfluidic chips.

  • 0.250 mm and 0.750 mm are suitable and mostly used for the fabrication of membranes
  • 1.2 mm and 2 mm are easier to mold and suitable for Flexdym beginners in the fabrication of microfluidic chips

This polymer is particularly interesting in life sciences: its biocompatibility make it simple to design any experiment. The self-sealing technology is not destructive, unlike plasma, vacuum or high temperature used in the sealing of other chips.

Optical or fluorescence measurements in a chip require the use of materials that show a high level of transparency (almost 90% transmittance), primarily in the UV and visible range. Flexdym fulfills these conditions. Indeed, it reaches the limit of 50% transmittance (which we considered to be an acceptable limit in transparency) at a wavelength of 295 nm. Flexdym features similar properties to the clearest materials. This transparency window is sufficiently wide for a large number of fluorophores, particularly the most popular fluorescent Cy3 and Cy5 dyes, which have excitation wavelengths at 550 and 650 nm and emission wavelengths at 570 and 670 nm, respectively. 

Principal characteristics

Flexdym sheet dimensions 150 x 150 mm
Thickness 200 µm / 750 µm / 1.3 mm
Tear Strength 15 kN/m
Tensile Strength 7.6 kN/m
Elongation 720 %
Molding Temperature 115-185 °C

Self-sealing and fast bonding

The Flexdym is easy to bond to either Flexdym or glass after molding.


Bonding temperature Flexdym chip on Flexdym Flexdym chip on glass
Room temperature 600 mbar 400 mbar
85 °C 5.5 bar 720 mbar


 Contact us for more informations.

Flexdym sheet (x10): Available thicknesses of 1.3 mm, 0.8 mm and 0.2 mm. Dimensions of 15 x 15 cm.

  • Do I need a heat press for Flexdym?

Yes, most heat presses or hot-embossers should work. A press that can mold at a pressure of at least 7 psi or above is ideal (a vacuum assisted press is not required). You may have to make small adjustments to optimize molding your chips. We offer a compact microfabrication kit, user friendly and plug and play system. Contact us for more informations.

  •  What size range is reliably micromolded with Flexdym?

The minimal microchannel width is 50 nm, and the depth range is 50 nm - 1 mm. However, microchannels between 1 µm and 1 mm are recommended with an aspect ratio (height to width) of 3:1 or less. Submicron structures and higher aspect ratios have also been achieved by some customers.

  • Which mold does Flexdym work best with?

Common molds used in the field of microfluidics work well. These include fragile molds, such as photoresists (e.g. SU‒8), and etched glass and silicon molds. Temperature resistant epoxy molds and traditional metallic molds (aluminum, nickel, brass molds) work also. Silicones such as PDMS work as well, however, be sure to choose a stiff silicone grade at least 20 Shore A durometers above Flexdym . We offer EPMO epoxy material to fabricate robust mold suited (up to 6’’ size) for Flexdym molding without the needs to treat it with anti-sticking agent.

  • How do I clean Flexdym?

Isopropyl alcohol, methanol or distilled water may be used. Flexdym has to be dry (air or oven dried) before molding to avoid bubbling or splays (cloudiness). Tape is also recommended to remove dust particles. We recommend working with Flexdym in a clean room or under a laminar hood to minimize particle contamination.

  • Is the Flexdym appropriate for my fluorescence applications?

Flexdym material is a transparent material and has a transmittance of 50% at 295 nm and upon 90% in the visible region.

  • How do I mold Flexdym as transparent as possible ?

We recommend molding Flexdym using a very smooth mold. Metallic molds should have a mirror finish. Using glass or other transparent molds, such as epoxy or other silicones will ensure a more transparent result.

  • Why do I keep getting tiny bubbles in the plastic when I mold Flexdym?

Your setup is likely too hot or Flexdym is not completely dry. Lower the temperature, decrease molding time, air/oven dry Flexdym, or perform molding in a low humidity condition to minimize bubbling. It may take some trial to optimize micromolding with Flexdym on your own setup.

  • What is the most effective way to sterilize Flexdym?

Ethylene oxide, gamma irradiation or autoclave will work.

  • Are Flexdym microfluidic chips used for cell culture?

While Flexdym is less permeable than PDMS, it still has sufficient air permeability to sustain cell cultures. Flexdym grades have successfully been used for neurons, hepatocytes, endothelial, dermal, stem-cells and IPSCs cells cultures among others. Flexdym is UPS Class VI and ISO 10993-5 biocompatible certified material (PVC, Latex and others phthalates free).

  • How do I seal Flexdym microchannels to a substrate?

Flexdym is a self-sealing material that you can bond with usual microfluidics thermoplastics materials (such as PC, POC, PS, PP), glass and Si. The bonding process does not require plasma assisted or UV adhesive processes. It can be bonded at room temperature. To reduce the time of bonding and/or to improve the bonding strength, a thermal bonding process can be used (maximum 90°C). Customers have successfully sealed Flexdym by binding it to a substrate and storing the chip in an oven for minutes to overnight.

  • How do I control the hydrophilicity of Flexdym surfaces?

In its pristine state, Flexdym is slightly hydrophobic. To achieve stable hydrophilic surfaces strategies that have been used on hard plastics can also be applied to Flexdym surfaces. These strategies include plasma treatment or coatings with hydrophilic materials, such as poly (vinyl alcohol), polyurethane, polyacrylate, (hydroxypropyl) methyl cellulose, polyvinylpyrrolidone, or hyaluronic acid. Multiple vendors offer hydrophilic coatings through licensing models or outsourcing. Key points to consider are the cost structure, the type of coating, the coating application (e.g. dip, spray, spin, film coats), any curing step (e.g. UV or heat), and any post-processing steps (e.g. sterilization, cleaning, or storage conditions) that may affect your final chip.

  • How do I create inlet and outlet holes for my microfluidic channels?

Traditional biopsy punches used with silicones will not work here. The use of a rotary/hand punch or a laser cutter is recommended. Self-sealing connection pads have been developed and ensure easy and leak-free connections with any tubing.

  • How do I prevent nonspecific binding?

Methods traditionally used to treat hard plastics generally work with Flexdym as well. For example, coating the surfaces with animal caseins or BSA (bovine serum albumin) has been used with success.

Payment Terms

You can either order and pay via credit card or invoice (through a purchase order). Please note that some products are not available for direct purchase: just click "Request a Quote" on the product page and fill in the form to get more informations!

Credit card 

  • Add your products to the cart
  • In the cart page, click on Proceed to Checkout
  • Complete your credit card informations (don't worry, we are using Stripe, a PCI-certified program specialized in online transactions)
  • That's it! You will receive an order confirmation within a few minutes, and our team will send you the invoice.


  • Add your products to the cart
  • In the website header, click on Request a Quote
  • Fill in the required informations, then click on Submit Quote
  • Our team will send you a quote shortly
  • After receiving the quote, just send your purchase order at contact@darwin-microfluidics.com
  • Our team will complete your purchase and send you the invoice!

If you wish to pay in USD, AUD or GBP, please specify it in your PO. We can add the converted value in the required currency to the quote if requested.


Worldwide shipping

We ship worldwide from our warehouse in France.

The shipping charges are calculated based on the weight of the package and the country of destination: you can estimate the shipping cost on the cart page. We try to offer you the best shipping rates and services, shipping all our orders through DHL Express. Generally, your order reaches your lab in only 2 to 3 days after we send it, no matter the destination! 

Please note that our shipping incoterms are DAP (Delivered At Place). Please contact us if you prefer using your own courrier account or have any question!

Customer Reviews

Based on 1 review

The team was very helpful in ordering exactly what we needed!!

Customer Reviews

Based on 1 review

The team was very helpful in ordering exactly what we needed!!