Biomimetics

During the 1950s, Otto Schmitt coined the term biomimetics in his doctoral thesis, to describe an electronic feedback circuit he designed to function in a similar way to neural networks, this invention latter became known as the Schmitt Trigger. Over the coming years several synonyms such as bionics, biomimesis, biomimicry, biognosis propped up in various parts of the world to describe developments inspired by the functional aspects of biological structures.

Biomimetics is a compound word of Greek origin: bio- meaning life and -mimesis meaning to copy: the outcome is the interpolation of natural mechanisms and structures into engineering design. The cross-disciplinary nature of the field has established a platform for technology transfer that transcends subject specific ’cultural’ barriers such as technical language thus functioning as a vehicle for ideas from biology to find useful applications in other fields.

Several historical examples are believed to be inspired by biological structures, such as the design of the Eiffel tower and the glass roof of the Crystal Palace that housed London’s Great Exhibition of the 1850’s. The first textile innovation linked to Biomimetics was the invention of the dry adhesive tape known as Velcro that was inspired by the hook mechanism found on the surface of burrs which enables them to attach onto animal fur in a way that is difficult to remove. However, such examples are probably serendipitous; biomimetic innovations today are the product of systematic study, with wide-reaching applications.

Today, one of the most popular biomimetic applications is known as the Lotus Effect. Inspired by the water-repellent and self-cleaning properties of the lotus leaf, the functionality was found to be due to a layer of wax crystals that covered the surface of the leaf. Originally this mechanism was interpreted into a masonry paint that would self-clean every time it rained (Lotusan tm). Recently, this has found application in the textile sector as a finish that delivers water, stain and dirt resistant properties to clothing without affecting the appearance or handle of the cloth.

Smart Fabrics and Interactive Textiles

Smart Fabrics and Interactive Textiles (SFITs) are defined as having an in-built ability to respond to external stimuli, including electrical, mechanical, thermal, chemical or magnetic

  • Market value for SFITs 2008: US$640M
  • Compound annual growth rate since 2005: 27%
  • Finished SFIT-based textiles current annual growth rate: 76%
  • Source: Textiles Intelligence Ltd, 2008

    Applications:

  • Athletic wear (active sportswear)
  • Performance wear (climbing, walking, skiing)
  • Comfort wear (underwear, nightwear)
  • Military (underwear, multi-climate clothing)
  • Health (hospital bed linens, wound dressings)
  • Agricultural technology (Geo-textiles, greenhouse screening panels, soil moisture control)
  • Technical solutions (Formula 1 protective clothing, firefighting, industrial clothing)
  • Industrial (filter & valve technology, building, packaging)
  • Upholstery (transport, domestic)

Pine Cone Effect

The Pine cone effect is a technology specifically designed to offer a solution to discomfort sensations caused by the build up of moisture in clothing microclimate experienced during travel in urban environments. The metropolitan landscape is laced with numerous over and underground networks forming vital passages that lead the traveller through a multitude of spaces, each defined by unique temperature, humidity and activity level. It is impossible to predict every eventuality and consequently accommodate in a selection of clothing to ensure comfort.

Modular clothing assemblies are currently used for the management of physiological comfort. The insulation and ventilation properties of an outfit are adjusted manually by the individual either by adding/ removing layers of clothing, compressing/ extending parts of garments and opening/ closing ventilation features. This method is compromised by factors such as limited availability of space and wearer’s ability to detect and respond to the onset of discomfort sensations.

Current smart systems rely on temperature as a stimulus for actuation, however Veronika’s research revealed that humidity is the ideal trigger. The study of moisture induced shape change in botanical structures (i.e. pinecone) inspired the design of a textile prototype able to adapt its air permeability in response to humidity changes in the microclimate of the clothing system.

Conventional fibres swell as they absorb moisture. This causes the yarn to swell which in turn reduces the porosity of the textile structure. Veronika has developed a textile which functions in the opposite manner; as it absorbs moisture the textile becomes more porous and in dry conditions the structure opens up like a pine cone, reducing permeability to air and increasing insulation properties