WINDLASS
Capillary windlass: exploiting spider thread properties to engineer bioinspired micron-sized motors, actuators, sensors or flexible electronic components
- Textile
- Sensors
- Electronics
- Actuator
- Spider silk
- Windlass
Market Challenges
Biological materials form a great source of inspiration for the design of new types of materials and structures. Spider's capture silk is a material exhibiting exceptional mechanical properties, in particular super-extensibility, adaptable rigidity, and surprising ability to relax and then quickly to re-tauten under compression to adapt itself to outside conditions. It receives from the spider very powerful biological aqueous glue droplets that are able to fold and to roll up the thread within themselves.
There is a growing demand for material innovation regarding the need for more powerful electronic components, for lightened structures in transport industry, for safety with more resistant materials, etc. Development of fibers inspired by spider silk could therefore be a solution.
Innovative solution
Biological materials form a great source of inspiration for the design of new types of materials and structures. Spider's capture silk is a material exhibiting exceptional mechanical properties, in particular super-extensibility, adaptable rigidity, and surprising ability to relax and then quickly to re-tauten under compression to adapt itself to outside conditions. It receives from the spider very powerful biological aqueous glue droplets that are able to fold and to roll up the thread within themselves.
There is a growing demand for material innovation regarding the need for more powerful electronic components, for lightened structures in transport industry, for safety with more resistant materials, etc. Development of fibers inspired by spider silk could therefore be a solution.
Development status
The proof of concept is done. It is based on the deposit of an oil droplet on a polyurethane micro-thread. The thread folds and rolls up within the droplets by capillary compression (figure 1b). The reserve of thread in droplets allows a significant extensibility.
- Extensibility: can reach 100 times its initial length
- No bending : the thread remains straight and adapts itself under compression
These results were validated on various materials:
- Thermoplastic PolyUrethane (TPU) with silicone oil
- Thermoplastic PolyUrethane (TPU) with ethanol
- Thermoplastic PolyUrethane (TPU) with a glycerin / ethanol mixture
- PolyLactic Acid (PLA) with silicone oil
- PolyCaproLactone (PCL) with silicone oil
- Glass nano-fiber with silicone oil
Suggested applications
- Flexible electronics (functionalization of electrical nano-wire): coating fiber with conducting materials produces tough, custom-shaped, flexible and electrically conducting fibers after drying and contraction
- Micro-motors, actuators, non-contact sensors: the droplet capillary forces generate micro-tensions in the fiber which can be used in micro-mechanical precision devices. Both supercontraction and cyclic contraction can be exploited for actuating applications
- Textile: these fibers can be used to make light textile, with very strong resistance and elasticity
- Artificial muscles these fibers can be used as a biomimetic muscle with an exceptional work density
Competitive advantages
- Slack length adaptability
- Extreme extensibility
- Excellent shock absorption
- Perfect reversibility (no fatigue)
- Adaptability: any material can be used as a windlass, provided it can be molded into sufficiently thin fibers
IP rights
Engineering & ICT | Number ref.: #MA00063
Textile, Sensors, Electronics, Actuator, Spider silk, Windlass
