This talk will present studies from our lab on the electrically induced adhesion of hydrogels and beads made from polyelectrolytes. The basic phenomenon involves crosslinked acrylate hydrogels made with either anionic co-monomers (such as sodium acrylate) or cationic co-monomers (such as aminated acrylates). When a rectangular strip of a cationic gel (connected to an anode) is contacted for just a few seconds with a strip of anionic gel (connected to a cathode) under a voltage of ~ 10 V, the two gel strips form a strong adhesive bond. When the polarity of the electrodes is reversed, the phenomenon is reversed, i.e., the gels can be easily detached.<br/><br/>While the above phenomenon of ‘electro-adhesion’ has been reported before for hydrogels, we show that it is much more general and widespread. Specifically, we can substitute either of the above gels with a spherical bead made using charged biopolymers such as chitosan or alginate. The same electro-adhesion works to join beads to gels, or two beads to each other. In turn, electro-adhesion can be applied for the pick-up and drop-off of soft cargo, and for the sorting of beads. Most interestingly, the same phenomenon also works with certain human tissues. That is, many tissues are anionic, and we show that cationic gels can be electro-adhered to them. We thereby demonstrate that cuts or tears in tissues can be electro-sealed using beads or gel strips. As an extreme case, two severed pieces of a tube can be stuck back together using a gel strip that spans both cut segments; this is thereby an example of a needleless suture using only hydrogels and an electric field.

Electrical “suturing” of polyelectrolyte hydrogels to reseal cut or damaged tissues

2019 Spring National Meeting

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