Protein Biomaterials with Muscle-like Water-Driven Actuation

Area of Science:

• Biomaterials Science
• Protein Engineering
• Soft Robotics

Background:

• Man-made shape-morphing biomaterials typically exhibit slow actuation compared to biological muscles.
• Developing artificial actuators with muscle-like speed and reversibility remains a significant challenge in biomaterials science.

Purpose of the Study:

• To engineer a novel class of protein-based actuators capable of rapid, reversible shape changes and motion.
• To mimic muscle contraction mechanisms using protein hydrogels.
• To explore applications in smart biomaterials and microactuators.

Main Methods:

• Utilized bovine serum albumin (BSA) hydrogels to create protein-based actuators.
• Induce fibril formation using varying ethanol concentrations (40-99%) to control shape changes.
• Investigated water-driven motion, including pulsating and rotational movement, triggered by ethanol retention.

Main Results:

• Achieved reversible shape changes in BSA hydrogels through ethanol-induced fibril formation and aggregation.
• Demonstrated fast, water-driven motion, including stochastic pulsations and rotational speeds up to 471 deg·s^-1 in a protein-based propeller motor.
• Showcased programmable shape changes occurring over minutes to hours, with shape recovery upon rehydration.

Conclusions:

• Developed a novel class of protein-based actuators with muscle-like actuation speeds and reversibility.
• The BSA hydrogel system offers a promising platform for creating advanced biomaterials with dynamic shape-morphing capabilities.
• Potential applications include bioresponsive systems, microactuators, and soft robotics.