Strain-induced color changes: Taking a clue from jellyfish and squid #Biomimicry #Biohacking
Researchers have developed material whose appearance can be reversibly altered by microscopic cracks and folds, via C&EN
Taking a clue from jellyfish and squids that quickly alter their appearance via muscle-controlled morphology changes in their bodies’ surface structures, researchers have designed polymeric materials that change appearance reversibly in response to mechanically induced folds and deformations
The animals exploit their color-changing abilities for camouflage and safety purposes. Scientists could use the new synthetic materials for those applications or as mechanical sensors, optical switches, and color-changing smart windows. The researchers, led by Luyi Sun of the University of Connecticut, made several types of so-called mechanochromic materials by depositing a transparent rigid film made from polyvinyl alcohol and a silicate compound on a flexible polydimethylsiloxane (PDMS) substrate. Stretching the simple bilayer material by 40% changes its appearance markedly yet reversibly from transparent to opaque. The optical changes result from stretch-induced microscopic cracks and folds that trap and scatter light. The team varied the material design to induce other optical effects. For example, they bonded an ultraviolet-shielding film to PDMS doped with a variety of fluorophores. Stretches and strains as small as 5% caused these materials to quickly change colors or change from nonluminescent to highly luminescent.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.