Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA.
Adv Mater. 2018 Jun;30(26):e1707461. doi: 10.1002/adma.201707461. Epub 2018 May 14.
Heating-triggered shape actuation is vital for biomedical applications. The likely overheating and subsequent damage of surrounding tissue, however, severely limit its utilization in vivo. Herein, cooling-triggered shapeshifting is achieved by designing dual-network hydrogels that integrate a permanent network for elastic energy storage and a reversible network of hydrophobic crosslinks for "freezing" temporary shapes when heated. Upon cooling to 10 °C, the hydrophobic interactions weaken and allow recovery of the original shape, and thus programmable shape alterations. Further, multiple temporary shapes can be encoded independently at either different temperatures or different times during the isothermal network formation. The ability of these hydrogels to shapeshift at benign conditions may revolutionize biomedical implants and soft robotics.
加热触发的形状驱动对于生物医学应用至关重要。然而，周围组织可能过热以及随后的损伤严重限制了其在体内的应用。在此，通过设计双重网络水凝胶实现了冷却触发的形状转变，该水凝胶集成了用于弹性储能的永久网络和疏水性交联的可逆网络，当加热时，疏水性交联用于“冻结”临时形状。冷却至 10°C 时，疏水性相互作用减弱，允许恢复原始形状，从而实现可编程的形状改变。此外，在等温网络形成过程中，多个临时形状可以分别在不同温度或不同时间独立编码。这些水凝胶在良性条件下进行形状转变的能力可能会彻底改变生物医学植入物和软机器人。
