This paper demonstrates a new type of interconnects to fulfill the primary function of axons: transmitting electrical signals over long distances and at high speeds. The interconnect, which we call "ionic cable", uses ions to transmit signals, and is built entirely with soft, elastic materials-elastomers and gels. The ionic cable is highly transparent, and remains functioning after being stretched nearly eight times its original length. We describe the design, theory and experiment of the ionic cable. We show that the diffusivity of the signals in the ionic cable is about 16 orders of magnitude higher than the diffusivity of ions. We demonstrate that the ionic cable transmits signals up to 100 MHz over 10 cm, and transmits music signals over meters. The ionic cable transmits enough power to turn on light-emitting diodes. Our theory shows that the ionic cables scale well, suggesting tremendous opportunities to create miniaturized ionic circuit.
This paper has been accepted by Extreme Mechanics Letters and is available online via
http://www.sciencedirect.com/science/article/pii/S2352431615000462
The vedio of using the transparent stretchable ionic cable to listen to music is also available online:
http://v.youku.com/v_show/id_XOTA5NDc0MDIw.html
We successfully synthesized a family of alginate/polyacrylamide hydrogels using various multivalent cations. These hydrogels exhibit exceptional mechanical properties. In particular, we found that the hydrogels cross-linked by trivalent cations are much stronger than those cross-linked by divalent cations. We demonstrate stretchability and toughness of the hydrogels by inflating a hydrogel sheet
into a large balloon, and the elasticity by using a hydrogel block as a vibration isolator in a forced vibration test. The excellent mechanical properties of these hydrogels may open up applications for hydrogels.
The paper has been accepted for publication in Applied Materials & Interface and can be downloaded from: