# In-Plane Material Handling: A Systematic Review
## 4 Discussion and Conclusions  
This paper, following a systematic methodology, presents the latest devices employed for the in-plane manipulation of materials. At the beginning of the study, three research questions were highlighted. The first two concern the characteristics and classification of systems used for handling tasks in the literature. The last question focuses on the manipulation of packages and parcels, which is a significant topic in material transport within the industry. Starting with a brief introduction of the methodology used to collect articles on the subject, this paper then presented an overview of the retrieved articles, first in terms of bibliometric data and subsequently through content analysis. The main outcome of this work is a comprehensive review of the in-plane manipulation systems present in the literature. A systematic analysis revealed that this subject is relatively new to surveys and review articles. The closest related reports include a book on distributed manipulation published in 2000 [96] and two papers published in 2015 focused solely on pneumatic systems [56; 97]. Among the retrieved articles, classes based on common features, fields of application, and working principles were identified. Consequently, a useful description of the functioning concepts and technology was provided to facilitate further research on the topic. Additionally, a comparison of these systems with a view to practical applications was included. Ultimately, a hint about an open research topic concerning simplified rotor handling surfaces was discussed. Specifically, in the final part of the answer to RQ3, the extensive use of motors in these devices was highlighted. Considering the trajectory of this field, there are several promising directions for future developments. Based on the analyses and research conducted on this topic, there appears to be a growing scientific interest due to the primary qualities of adaptability and flexibility. The authors believe future developments will be driven by technological advancements, particularly in materials science; robotics; and, most importantly, artificial intelligence (AI). New materials and manufacturing processes, among other things, will enable the further miniaturization of parts, improve system performance through reduced friction, enhance the durability of components, and offer improved magnetic properties. Advancements in robotics are equally crucial, as more sophisticated and miniaturized robotic systems can enhance the precision and versatility of in-plane manipulation devices, allowing them to handle a wider array of tasks with greater dexterity and control. Furthermore, AI is expected to play a pivotal role in the evolution of in-plane manipulation systems. AI can optimize the operation of these systems through the use of advanced algorithms, enabling better path planning, object recognition, and adaptive control. This convergence of technologies will significantly enhance the efficiency and capabilities of in-plane manipulation systems, meeting the growing demand for flexible and adaptable solutions in various industries. In conclusion, in light of the presented analyses and the described potential future developments, this paper serves as a valuable resource and guide for future advancements in in-plane handling systems. Conceptualization, E.B., F.J.B.D. and J.A.Y.-F.; methodology, E.B. ; software, E.B. ; validation, E.B. ; formal analysis, E.B. ; investigation, E.B. ; writing--original draft preparation, E.B. ; writing--review and editing, E.B., F.J.B.D. and J.A.Y.-F.; visualization, E.B. ; supervision, F.J.B.D. and J.A.Y.-F.; project administration, F.J.B.D. and J.A.Y.-F. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. Data Availability Statement: Data are contained within the article.