Advanced Applications of Soft Matter

Actuators for Soft Robotics

Actuators are materials that can move, similar to artificial muscles. In traditional robotics, movement is generated by motors. In order to develop soft robotics, a new method is required that can allow for quick, strong, repeatable motions, but does not require high modulus materials, such as metals. We have developed a method whereby a stiff fabric interphase provides mechanical support for silicone elastomer and polyampholyte hydrogel surface layers. By preferentially swelling or deswelling one of these layers, we can enable controlled, cyclable movement.

Publications:

  • Hubbard, A. M.; Cui, W.; Huang, Y.; Takahashi, R.; Dickey, M. D.; Genzer, J.; King, D. R.*; Gong, J. P. “Hydrogel/Elastomer Laminates Bonded via Fabric Interphases for Stimuli-Responsive Actuators.” Matter (Cell Press) 2019, 1 (3): 674–689.


Hydrogels as Synthetic Biomaterials

Biomaterials have some specific mechanical properties that are extremely difficult to achieve in synthetic materials, such as high strength and toughness and high fatigue resistance, all while maintaining a highly hydrated state. It is not possible to achieve all of these properties simultaneously in a homogenous material, and we therefore aim to utilize composite materials to achieve these properties. Beyond just mechanical response, synthetic biomaterials must be able to integrate well within the human body. They must be biocompatible, without causing immune system responses or rejection. Furthermore, they need to be able to integrate with already present biological tissues, either to improve healing, or to act as a permanent prosthetic.

Triphasic Living Hydrogels

人体は驚くほど複雑であり、重要な器官系では液体・固体・気体が一体となって機能しています。例えば心臓を中心とした循環系は、全身に液体を送り込み、フィードバックセンサーに基づいて積極的に栄養を供給することで、適切な成長や治癒を可能としています。骨格系は、全身の支柱と機械的な補強を担い、スムーズな運動と不意の衝撃からの保護を可能とします。呼吸系は、酸素の吸収と二酸化炭素の放出を可能にし、代謝プロセスの条件を制御しています。これらの例から、物質の三態が連携して、人間の生命を支える活性物質を生成していることが分かります。つまり、単一の物質の相が単独でこれらの機能をすべて網羅することはできないのです。人工バイオマテリアル創製のためには、生体適合性と堅牢な機械的性質を維持しながら、三相(液体・気体・固体)の活性物質をサポートするために拡張可能な構造体を開発する必要があります。