The researchers synthesized a polymer that can change its volume more than 100 times under the influence of a weak electric current, switching between the solid phase and the gel.
Materials that change their size independing on temperature or pH have been available for a long time, and are used in various control units, electromechanical systems, robotics. However, until now, scientists have managed to achieve a maximum of a twofold increase in volume under the influence of electricity.
A team from Linkoping University has opened a unique conductive polymer which by phasetransition can change its volume very strongly and reversibly. The increase occurs when the material is placed in the electrolyte and subjected to a weak electric voltage of +0.8 V, but if then a negative voltage of -0.8 V is applied, then it begins to compress, almost to its original volume.
Under the influence of electrical pulses +0.5 Vor +0.8 V, the material changes its internal structure, then begins to absorb water, turning into a gel, which eventually increases by 14 or 120 times compared to the original volume, respectively. With repeated use of pulses of +/- 0.5 V, the polymer expands by about 300% compared to the previous compressed state. These changes are reversible.
Using new material, scientists have developedsmart sponge, the pore size of which they can control electronically. According to them, such a dynamically variable filter can be used in production, medicine, biochemistry.
Recall that recently, scientists also introduced the blackest material today, absorbing 99.96% of the light.</p>