Surface Modifying Technique on Plastic Material

Plastic Joining Technology with Molecular-Level Surface Modification

Are you facing challenges with plastic joining when the joining surfaces have precision shapes?

The methods commonly used to bond plastics together are using adhesives or heat fusion. However, both have their weaknesses and may not always fulfill the desired function. Surface modification joining technology opens up new options to address these issues.

Are you facing challenges with bonding or joining plastics?

  • When attempting to perform thermal bonding on fine shapes, there is a risk that the heat will cause the shapes to melt and collapse. Similarly, when using adhesives, there is a possibility that the adhesive will flow into the recesses of the fine shapes, affecting areas other than the bonding surface.
  • In microfluidic devices and organ-on-a-chip used to validate cellular responses and drug efficacy, the leaching of adhesives may potentially affect experimental outcomes.
  • The plastic I want to use has properties that prevent it from being bonded with adhesives.

Please make use of the plastic surface modification-based joining technology, a novel method to address these challenges, in your device development.

【Here’s the Difference】Technology for Joining Plastics by Modifying Joining Surfaces at the Molecular Level

Unlike traditional thermal welding or adhesives, this method completely alters the nature of the joining surfaces at the molecular level. There’s no concern about shape distortion or leaching of substances contained in the adhesive. Therefore, it’s suitable for applications such as microfluidic devices and organ-on-a-chips, where parts with finely machined grooves and holes need to be joined.

Microchannels created by joining with surface modification. The narrowest central channel has a width of 50 µm.

【Achievements】Resins with poor adhesion can be joined together, as well as COP resins with COP resins and COC resins with COC resins.

COP resins and COC resins have various characteristics and are expected to be widely used in fields such as life sciences, food packaging, and optical products. However, due to their poor adhesion properties, they were previously deemed unsuitable for applications requiring bonding of surfaces with microstructures, such as microfluidic channels. Nevertheless, with the advancement of surface modification technology, it is now possible to join these materials, expanding their potential applications even further.

The Characteristics of COP and COC Resins

  • Due to their low water absorption and excellent dimensional stability under high humidity conditions, they exhibit high dimensional accuracy even in environments such as in vivo or in liquid media. Additionally, they are suitable for precision molding as they experience minimal warpage deformation during molding.
  • Boasting high transparency comparable to acrylic resins, it is suitable for containers and microplates used in optical measurements.
  • Lightweight compared to other common resins due to its low specific gravity.
  • Resistant to heat similar to polycarbonate and autoclavable.
  • Contains very few impurities and is suitable for medical equipment.
  • With low retention properties, to the extent that it’s used in blood analysis cells.

COP and COC resins possess numerous highly attractive characteristics as mentioned above. The success of this bonding has made it possible to develop dreamlike devices that combine high optical performance with biocompatibility.

【Future Developments】Actively Researching to Expand the Range of Joinable Materials!

We are currently conducting research on joining other resins and dissimilar materials such as PMMA and PC. Please feel free to inquire about the joining possibilities of various materials.

The Applicability of Plastic Surface Modification Technology

When performing cell culture, it is known that the wettability (hydrophilicity) of the substrate surface, such as dishes, and the functional groups and charges on the surface affect cell proliferation and differentiation. In particular, the culture of adherent cells requires that cells adhere to the substrate surface, and it is said that the compatibility between the surface charge of the cell surface and the substrate is the key to culture. Since this compatibility varies depending on the cell type, various surface modification techniques and coatings are being attempted in various fields. We are also accumulating our own research and know-how in the development of culture plates.

Recruitment of Partner Companies

We are seeking partner companies that can leverage plastic surface modification technology.

Plastic surface modification technology is a versatile technique that holds potential for various applications such as joining, hydrophilic modification, cell scaffold formation, and more. We are actively seeking partnership opportunities with companies beyond Watson products to utilize this technology. Please feel free to contact us for further inquiries.


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