Team:Erlangen Nuremberg
Development of Novel Biocompatible Tissue for the Application as Artificial Muscles in Robotics and Medicine
Abstract
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.
