###### Abstract
The first feature that makes RSLDE technique different from other techniques is the elimination of the necessity of heating the extraction system, as the action exerted is of a mechanical type. In comparison, current extraction techniques (percolation, Soxblet, steam distillation, ultrasound) tend to increase temperature to improve extraction efficiency in order to enhance extraction yield, according to the well-known Fick's law [11]. Extraction by diffusion and osmosis are temperature-dependent phenomena. However, in case of thermolabile compounds, the increase in temperature may result in their degradation; therefore, the best operating conditions will be chosen by controlling the maximum temperature at which the bioactive compounds of the plant matrix will not be degraded. The other advantage of RSLDE is linked to the scalability of the process; indeed, a lab-scale plant has first been developed, with an internal volume between 0.5 L to 2 L. In order to verify the replicability on a large scale, a pilot plant has been also built, whose mean volume is 40 L. Finally, the successful use of these two previous versions brought the possibility of providing an industrial scale layout, with a volume of 200 L.  
Since the extraction action in RSLDE is of a mechanical type, a few extraction cycles (about twenty) of 2 h each could be enough to obtain high yields of extraction with any solid matrix that contains extractable materials. Therefore, this is the same assumption on which all the conventional extraction processes are based. Even if maceration is considered the official extraction method according to Pharmacopoeia guidelines for active principles from official plants [12], RSLDE is fast and exhaustive at the same time [13]. Moreover, RSLDE gives the possibility to carry out the aqueous extraction of vegetables, thanks to the reduced times, which is impossible to achieve by maceration because of the fermentation process that takes place more rapidly than the extraction of actives. As a very common example for this general assumption, we could consider the observation that common vegetables cannot be extracted only with water at room temperature and pressure. It is well-known that in these cases, it is necessary to add preservatives to the water in order to avoid fermentation or microbiological growth. Moreover, RSLDE is an inexpensive technique and requires minimal energy expenditure when compared to other innovative extraction techniques, such as Supercritical Fluid Extraction (SFE) [14] or Accelerated Solvent Extraction (ASE) [15]. Therefore, RSLDE is a valid alternative to existing extraction techniques and finds applications in the extraction of active ingredients of different origins [16]. The fields of application of the RSLDE are diverse, such as the pharmaceutical, cosmetic, herbal, but also the food and beverage fields [17]. These applications can be realized on both laboratory and industrial scale due to the scalability of machineries. At an industrial level, the extraction is generally carried out using percolators, as an alternative to the slow process of maceration, that allows one to obtain a large amount of extract in a short time, using a mild heating (between 30 \({}^{\circ}\)C and 50 \({}^{\circ}\)C) of the system. Despite the use of percolation process and a higher temperature, the overall yield of the process is not optimal (<60%) [18; 19], and the solid matrix is not completely exhausted. Therefore, the matrix can be considered as waste material that can be used as a by-product and extracted completely using RSLDE. In addition, the importance of obtaining extracts with non-degraded active ingredients lies in the fact that in this way, the pharmacological activity of the extracts themselves increases.