Difference between revisions of "Team:Erlangen Nuremberg"

Development of Novel Biocompatible Tissue for the Application as Artificial Muscles in Robotics and Medicine

The development of artificial muscles attracts wide interest for industrial and medical

applications. Regarding manufacturing, robotic devices with synthetic muscles are able to

handle softer materials more precisely. Moreover, artificial musculatures in medical

prostheses can improve the wearing comfort while conveying a rather natural feeling.

Currently, muscle-like contractions can be obtained by capacitor systems or by molecular

machines incorporating tissue. This project aims to replace the common materials in both

branches by biological tissue. While increasing ecological friendliness and the compatibility

with human tissue, those fabricated compositions can compete with human biological

material.

Like a capacitor, the dielectric elastomer actuator (DEA) comprises two lightweight and

flexible electrodes separated by an insulating elastomeric layer. In a first set of experiments,

the elastomer layers in the capacitor-based muscle need to be replaced by appropriate protein

structures. P-Pili with their excellent elastic properties and proteins with high amounts of

helical secondary architecture are to be tested for this approach. In a next step, the currently

used light weighted graphene or carbon nanotube layers need to be replaced by the Pili to

provide conductivity and flexibility comparable to the carbon nanotubes. Both fibril types can

be easily expressed in Geobacter sulflurreducens and Escherichia coli in a large scale, which

makes the overall system extremely feasible since one organism can provide the whole

material.

Another tissue with muscle-like contractions will be fabricated through polymers with

integrated molecular machines. Herein, the latter are based on azo dyes capable of having

their entire network contracted by light irradiation. The biopolymer matrix is fabricated by

Escherichia coli and consists of catcher-tag systems modified with a biotin-accepting anchor.

The molecular machines attach to the biopolymer tissue via biotin and biotin acceptor

interactions. Due to the crosslinking of the single protein strains the stiffness of the resulting

tissue can be adjusted accurately.

In both cases, the achieved tissues are cell-free and can immediately be adapted to the system.

Within the scope of the project, the construction of a DEA-prototype is planned, since the

realization of electrical stimuli is more feasible than through photo-induced signals.