# A Review on Recent Trends and Applications of IoT in Additive Manufacturing
## 2 IOT-Enabled 3D Printing Applications
### 3D Bioprinters
Their team accomplished cell-loaded bioprinting using a commercial SLA printer a year later [74]. The same year saw the development of 3D tissue containing only cells (no scaffold). The year 2006 saw the use of electrohydrodynamic jetting for the deposition of live cells [75]. [PERSON] et al. produced scaffold-free vascular tissue by bioprinting in 2009 [76]. In 2012, [PERSON] et al. performed in situ bioprinting on mouse models [77]. In the years that followed, several innovative bioprinting items were introduced, including articular cartilage and an artificial liver in 2012, and tissue integration with the circulatory system in 2014, etc. [78; 79]. [PERSON] et al. employed a coaxial technique for the manufacturing of tubular structures in 2015 [80]. In 2016, [PERSON] et al. implemented DLP-based quick continuous optical 3D printing [81]. The same year, the research group of [PERSON] produced a cartilage model utilizing an integrated tissue-organ printer (ITOP) [81]. [PERSON] et al. succeeded in producing a superior scaled-down heart in 2019 [82]. A few months later, [PERSON] et al. [83] accomplished the bioprinting of collagen human hearts at various sizes using the freeform reversible embedding of suspended hydrogels (FRESH) method [66]. Bioprinting technology has advanced significantly, yet it faces challenges such as insufficient biocompatibility, hazardous breakdown products, and a dearth of bioactive ligands [63]. The challenges can be solved by the Internet of things (IoT) using sensors. The IoT monitors the entire bioprinting process with accuracy and repeatability. If the entire bioprinting environment is integrated with the IoT then the sensors in the IoT will take care of all the parameters throughout the process. That is, first the IoT will find the best method for the tissues from the different bioprinting technologies. Then the IoT will select the material and parameters for the printing process. If any toxic waste is produced during the bioprinting process, it is separated and stored properly by the sensors of the IoT. The IoT will control the biomaterial deposition so there is good biocompatibility between the cells of the tissues. The IoT also integrates other technologies, such as 3D scanning in bioprinting. If an organ is damaged in an accident or for any other reason, then that organ should be replaced with a new organ with the same topology and geometry within a limited time; in this case, the IoT can use 3D scanning technology to get information on the topology and geometry from the damaged organ. Future research activities will concentrate on the creation of innovative 3D bioprinting materials with superior biocompatibility, enhanced printing capability, and acceptable mechanical qualities. Various uses of 3D printing include the study of cellular behavior, tissue pharmacodynamics, and toxicological pathways, to name a few. Despite the excellent accuracy and repeatability of 3D printers, the printing of organs and functioning tissues with complete architectures still requires assembly layer-by-layer with \"bioglue.\" Bionics with sufficient biocompatibility and mechanical strength that can be employed to produce biological functions are the primary technological obstacles. For soft and hard tissue engineering, hydrogels and ceramics have been utilized, respectively. In the meanwhile, personalized 3D printing technology will result in a number of regulatory obstacles pertaining to printed product oversight. Nevertheless, it is of the utmost importance that management establishes and improves the appropriate rules and regulations in order to ensure the continued and sustainable growth of 3D printing technology. Printing micro-organs, such as pancreas islet tissues that operate in the absence of the whole pancreas structure, will likely make significant development in the near future, which will assist hundreds of millions of diabetes people worldwide. Such changes have successfully resulted in the manufacture of micro-liver samples for drug metabolism testing.