Soft Magnetostrictive Actuator String with Cellulose Nanofiber Skin

Area of Science:

• Biomaterials Engineering
• Nanotechnology
• Microbiology

Background:

• Forming cellulose nanofibrous skins in liquid cultures presents challenges like particle diffusion and limited oxygen for bacteria.
• Existing methods struggle with controlling bacterial growth and particle distribution for advanced material fabrication.

Purpose of the Study:

• To develop a novel composite-actuating string using magnetic nanoparticles (MNPs) and Gluconacetobacter xylinus.
• To engineer a cellulose nanofibrous skin actuator responsive to magnetic fields for medical applications.

Main Methods:

• Fabrication of a composite-actuating string embedding MNPs and G. xylinus within a solid matrix of hydrophobic microparticles.
• Utilizing G. xylinus's cellulose synthesis to create a dense nanofibrous skin around MNPs.
• Testing the actuator string's magnetic responsiveness, deformability, and performance as an endoscopic guidewire.

Main Results:

• A functional actuator string was successfully fabricated, integrating MNPs within a cellulose nanofiber matrix synthesized by G. xylinus.
• The nanofibrous string demonstrated responsiveness to external magnetic fields, enabling controlled bending.
• The string exhibited excellent softness and plastic deformability, allowing it to adapt to tubular structures and reduce friction.

Conclusions:

• The developed magnetic cellulose nanofibrous actuator string offers a promising solution for challenging endoscopic guidewire applications.
• Its unique properties, including magnetic actuation and deformability, facilitate navigation within complex anatomical pathways.
• This innovation advances the use of bacterial cellulose in soft robotics and minimally invasive medical devices.