  Along with the proliferation of sensors and of smart devices, an explosive
volume of data will be generated. However, restricted by their limited physical
sizes and low manufacturing costs, these wireless devices are typically
equipped with limited computational capabilities and battery lives and thus
incapable of processing data time-efficiently. To overcome this issue, the
paradigm of mobile edge computing (MEC) is proposed, where wireless devices may
offload all or a fraction of their computation tasks to their nearby computing
nodes deployed at the network edge. At the time of writing, the benefits of MEC
systems have not been fully exploited, predominately because the computation
offloading link is still far from the perfect. In this article, we propose to
empower the MEC systems by exploiting the emerging technique of reconfigurable
intelligent surfaces, which is capable of reconfiguring the wireless
propagation environments and hence of enhancing the offloading links. The
beneficial role of RISs can be exploited by jointly optimizing both the RISs as
well as communications and computing resource allocations of MEC systems, which
imposes new research challenges on the systemic design and thus necessitates a
specific investigation. Against this background, this article provides an
overview of RIS-assisted MEC systems and highlights their four use cases as
well as their design challenges and solutions. Then their advantageous
performance is validated with the aid of a specific case study. Finally, a
guide on future research opportunities is elucidated.
