Materials

The NASCENCE project aims to model, understand and exploit the behaviour of evolving nanosystems. The materials chosen to create these evolvable nanosystems are crucial to the success of the project.

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6x6 Microelectrode array slide and zoomed view of the electrode array.

NASCENCE materials are custom made within the consortium. Material samples are placed on custom designed glass slides including a microelectrode array with a connector to be interfaced with the interface hardware of NASCENCE.

To achieve the desired results a broad statement of what should make a good “computational material” has been agreed:

“The ideal material":

  • Has a complex, configurable, semi-conducting structure
  • Responds instantly and consistently to a wide range of voltages
  • Relaxes into an un-configured or random state when voltage is removed
  • Robust to changes in the environment (light, heat, electromagnetic signals etc)
  • Consistent between devices

Many of these statements contradict each other, for example making a material that can be reconfigured will naturally make it less stable than a fixed material. Throughout the project the aim is to develop a material that strikes a balance between all of these desired properties.

Possible material systems include:

  • Pure carbon nanotubes (SWCNT/MWCNT/unsorted/semiconducting/metallic)
  • Carbon nanotube/polymer composites
  • Conducting polymers
  • Nanoparticles
  • Graphene
  • Graphene/graphene oxide gels
  • Liquid crystals

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Low and high concentration of carbon nanotubes deposited on a microelectrode array.

As well as the type of material, the physical state of the material is also important, i.e. liquid or solid. Solid phase materials (pure nanotubes, dried polymers etc) offer greater stability but no opportunity for re-organisation during optimisation. Liquid phase materials (liquid crystals/liquid crystal mixtures) allow movement of the conducting species but will be less stable.

To date, mixtures of single walled carbon nanotubes and poly(butyl methacrylate) have proven promising as dried, fixed materials. Future work with mixtures of liquid crystals and SWCNTs will allow exploitation of movement of the conducting species due to alignment within the host material.

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Illustration of NASCENCE material sample and the connector to the interface hardware.