A micropump induces the flow of its surrounding fluids and is extremely promising in a variety of applications such as chemical sensing or mass transportation. However, it is still challenging to manipulate its pumping direction. In this study, we examine a binary micropump based on perovskite and poly[(2-methoxy-5-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV). The micropump is operational under the influence of light. Light exhibits significant versatility in controlling the pumping phenomenon of the micropump. It governs the start and stop and also regulates the velocity and directions. The direction control signifies immense opportunities for the development of micropumps with unprecedented pumping behaviors and functions (such as heartbeat-like pumping, rectification, and amplification). This makes them potentially useful in various fields. Hence, it is expected that the micropump reported in the current study could act as a key step towards the further development of more sophisticated micropumps for diverse applications.

In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not only can the resulting micromotor move autonomously on the surface of water for a long period of time (~40 min) due to the Marangoni effect, but it also exhibits a pH sensing behavior due to variations in the surface tension caused by the release of surfactant under different pH conditions. More interestingly, we reveal that the motion-based pH sensing property is size-dependent, with smaller structures exhibiting a higher sensitivity. In addition, since polycaprolactone is a biodegradable material, the micromotor described in this study can be easily degraded in solution. Hence, features such as one-step fabrication, motion readout, and biodegradability render this micromotor an attractive candidate for sensing applications.