A screening experiment was paired with research observing the past, present and futures of additive manufacturing (a.k.a. rapid prototyping, 3D printing), radio frequency identification, and supply chain management. The experiment tested different properties of objects created with a desktop fused deposition modelling printer to observe if any single factors or interactions affected the read range of embedded passive UHF RFID inlay.
The combination of material and infill percentage had a statistically significant effect on read range, however the analysis is weak since the data could not justify the normality assumption of ANOVA. Furthermore, the size of the effect was small enough to deny any practical difference. From the experiment and research, several presently capable interactions between AM and RFID were commented on. Future interactions between AM, RFID and SCM were also discussed, and a common relationship to physical objects was drawn.
Different sizes of supply chains are occasionally recognized in literature. Scott, Lundgren and Thompson break SCs into simple and extended; whereas simple chains recognize a level above and below the focus organization, extended chains look beyond the firms immediately upstream and downstream (Figure 1). Figure 1 also demonstrates a bilateral flow between companies: materials flow forward (from raw material extractors to final customers) while information and funds flow backward (from final customers to raw material extractors).
Figure 2 (Tajima, 270) shows two paths RFID provides towards gaining short-term advantages and long-term advantages. Short term competitive advantages come directly from exploiting the technology for the use it was intended for, which likely leads to direct process adjustment and improvement, and eventually an advantage. The long term advantages come from using RFID to explore facets of the manufacturing, distributing, storing, and selling that may have been previously unseen.
Test prints of the substrate designs was done with ABS and PLA. After verifying the designs would print with no issues, and that the depressions would fit a real inlay without noticeable extra space, the substrate designs were replicated to fit as many on the build plate as possible. Since all the post-processing (including taking the printed object off the build plate and removing any support structures) of FDM printers is currently manual (for all printers, not just the one used in this experiment), print jobs cannot be queued. This means that user intervention is required to complete one print job and initiate the next.
As discussed in the RFID literature review section, every system is made of tags, readers/antennas, and a back end. The remaining system components were borrowed from Poly GAIT, the Cal Poly Laboratory for Global Automatic Identification Technologies directed by Dr. Tali Freed. The lab has many Poynting circularly-polarized antennas that have proven to be reliable. A structure made from PVC was used to position an antenna and keep it at a constant height and orientation (Figure 8, Note: three antenna are shown but only one was connected to the reader to remove the possibility of outgoing wave interference).
In this experiment, however, the three-factor effect had a p-value that could be eliminated in a study with a higher level of significance (0.95). In case this study inspires future research and the experimenter prefers α = 0.05, interaction plots for both material * thickness and material * infill * thickness are included (Figures 9 and 10). The magnitude of both effects are on the scale of hundredths of an inch. The researcher believes that such small effects do not make a practical difference to the read range of a passive UHF RFID tag.
The magnitude of both effects are on the scale of hundredths of an inch. The researcher believes that such small effects do not make a practical difference to the read range of a passive UHF RFID tag. Furthermore, the data does not strongly support the assumptions of normality and equal variance that must be met for a valid ANOVA test. Hence, the applicable conclusion of this experiment is that no claim can be made for material, infill, speed, or thickness of a 3D printed object having an effect on passive UHF tag read range.
However, the original had to be missing from its rightful owner to counterfeit the key and, if the victim noticed at any time prior to duplication, the locks could be changed. The author demonstrated the ability of a key to be inconspicuously recreated through 3D printing with two pictures of his parents house key captured by a cell phone camera (Figures 11 and 12).
It took 30 seconds to take pictures of the front and side profiles of the key and measure its width and length. A working plastic replicate (Figure 14) was drafted in a CAD program (Figure 13), converted to gcode, and printed within an hour. The value of the key itself is a few dollars, but access to a household or business (with no signs of forced entry) is easily worth five or more digits. Savvy security companies can use this frightening reality to push for the ubiquitous adoption of RFID-based access control systems.
Additive manufacturing began to transform research and development in the 1980s and, through persistent maturation, has become a disruptive technology. Without many of the design constraints of subtractive and net shape manufacturing techniques, additive manufacturing has spurred innovation. This paper sought to investigate how advances in additive manufacturing may transform the radio frequency identification industry and supply chain management. A screening experiment was designed to test the feasibility of integrating Passive UHF RFID into objects created with a FDM printer. After testing different plastic materials, infill percentages, print speeds, and object thicknesses, no factor appeared to have a practical effect on RFID read range. Several applications taken from the experiment results and textual research were discussed.
Some topics like using RFID to identify 3D printed objects, providing anti counterfeiting measures with RFID, and using additive manufacturing to customize RFID form factor are immediately relevant. Other discussions looked into future interactions between RFID, AM and SCM. A theory of the symbiotic relationships between the three industries centered on physical objects stands as the culmination of the experiment and literary research. Academics and professionals concerned with any of the subjects examined in this study should constantly be following news and trends in each industry to ensure collaboration and maximum potential growth.
Source: California Polytechnic State University
Author: San Luis Obispo