Force-controlled release of small molecules offers great promise for the delivery of drugs and the release of healing or reporting agents in a medical or materials context^1,2,3. In polymer mechanochemistry, polymers are used as actuators to stretch mechanosensitive molecules (mechanophores)⁴. This technique has enabled the release of molecular cargo by rearrangement, as a direct^5,6 or indirect^7,8,9,10 consequence of bond scission in a mechanophore, or by dissociation of cage¹¹, supramolecular¹² or metal complexes^13,14, and even by ‘flex activation’^15,16. However, the systems described so far are limited in the diversity and/or quantity of the molecules released per stretching event^1,2. This is due to the difficulty in iteratively activating scissile mechanophores, as the actuating polymers will dissociate after the first activation. Physical encapsulation strategies can be used to deliver a larger cargo load, but these are often subject to non-specific (that is, non-mechanical) release³. Here we show that a rotaxane (an interlocked molecule in which a macrocycle is trapped on a stoppered axle) acts as an efficient actuator to trigger the release of cargo molecules appended to its axle. The release of up to five cargo molecules per rotaxane actuator was demonstrated in solution, by ultrasonication, and in bulk, by compression, achieving a release efficiency of up to 71% and 30%, respectively, which places this rotaxane device among the most efficient release systems achieved so far¹. We also demonstrate the release of three representative functional molecules (a drug, a fluorescent tag and an organocatalyst), and we anticipate that a large variety of cargo molecules could be released with this device. This rotaxane actuator provides a versatile platform for various force-controlled release applications.

小分子的力控释放为医疗或材料环境中的药物输送和愈合或报告剂的释放提供了巨大的希望^1,2,3 。在聚合物机械化学中，聚合物被用作执行器来拉伸机械敏感分子（机械团） ⁴ 。该技术能够通过重排释放分子货物，作为机械载体中键断裂的直接^5,6或间接^7,8,9,10后果，或通过笼¹¹ 、超分子¹²或金属络合物^13,14的解离，甚至通过“弹性激活” ^15,16 。然而，迄今为止描述的系统在每次拉伸事件释放的分子的多样性和/或数量方面受到限制^1,2 。这是由于迭代激活可分裂机械团的困难，因为驱动聚合物将在第一次激活后解离。物理封装策略可用于交付更大的货物负载，但这些策略通常会受到非特定（即非机械）释放^{3 的}影响。在这里，我们展示了轮烷（一种互锁分子，其中大环被捕获在带塞的轴上）充当有效的致动器来触发附加到其轴上的货物分子的释放。通过超声波处理在溶液中和通过压缩在散装中证明每个轮烷致动器可释放多达 5 个货物分子，释放效率分别高达 71% 和 30%，这使该轮烷装置跻身最高效的装置之列。迄今为止取得的发布系统¹ ． 我们还演示了三种代表性功能分子（药物、荧光标签和有机催化剂）的释放，并且我们预计该设备可以释放多种货物分子。该轮烷执行器为各种力控释放应用提供了多功能平台。