Desktop Printers Research Articles

Effect of the filling percentage on tensile strength in 3D desktop printing for different printing patterns, using a randomized design of experiments

The evaluation of the tensile strength of printed parts by means of fused deposition modeling (FDM) or fused filament fabrication (FFF) is essential, since parts whose resistance does not differ significantly depending on the percentage of filling used can be obtained, optimizing the use of the material. The present work details the analysis of polylactic acid (PLA) specimens manufactured according to ASTM D 638 with different percentages for the most commonly used filling patterns (Honeycomb, Octagram, Stars, Archimedean, Hilbert and Triangles). With the help of an analysis of variance and a design of experiments with a single factor, the appropriate percentages for printing parts according to the desired filling pattern are obtained.

Build Time Estimation for Fused Filament Fabrication via Average Printing Speed.

Build time is a key issue in additive manufacturing, but even nowadays, its accurate estimation is challenging. This work proposes a build time estimation method for fused filament fabrication (FFF) based on an average printing speed model. It captures the printer kinematics by fitting printing speed measurements for different interpolation segment lengths and changes of direction along the printing path. Unlike analytical approaches, printer users do not need to know the printer kinematics parameters such as maximum speed and acceleration or how the printer movement is programmed to obtain an accurate estimation. To build the proposed model, few measurements are needed. Two approaches are proposed: a fitting procedure via linear and power approximations, and a Coons patch. The procedure was applied to three desktop FFF printers, and different infill patterns and part shapes were tested. The proposed method provides a robust and accurate estimation with a maximum relative error below 8.5%.

Synthesising polymeric dispersants to apply to carbon black pigmented mill bases for use in ink‐jet inks

AbstractDyes are an important component of drop‐on‐demand ink‐jet inks and are commonly used in desktop printers. While they offer bright, vivid colour, these dyes exhibit poor light and water fastness. To combat this, researchers have started using pigmented ink‐jet inks instead of dye‐based inks to improve light and water fastness, but the pigments are insoluble in ink vehicles. To use pigments, dispersants must be applied; however, this is a delicate process because the properties of the dispersant substantially affect how the pigmented mill base must be prepared. In this study, polymeric dispersants are synthesised based on the properties and ratios of monomers and the molecular weights of polymers. In total, 14 types of polymeric dispersants are synthesised and examined, with special attention paid to the dispersing properties of particle size reduction and the stability of the pigmented mill base used to prepare drop‐on‐demand ink‐jet inks. This study describes the synthesis of the dispersants in terms of their suitability for commercial application.

Personal Printers and Ink in São Paulo and Recife: Getting New Things Done


 
 
 Team ethnography for a desktop printer manufacturer in two Brazilian cities on desktop printers and printing is reported here. Our team aimed to resolve an initial puzzle about printers and ink and explored what was going on with the desktop printers as they were acquired, used, and maintained. Our work expanded to encompass the LAN house, small shops, often operated by entrepreneurs, that provide access to the Internet and to printing. The research led to an intrapreneurial modification of a long-standing desktop printer business model by the client. The article concludes by exploring how entrepreneurs (shop owners and teams doing ethnography for hire) and intrapreneurs (those who venture from within a large enterprise) widen the scope of their venturing to encompass wider social and political issues like moral panic, poverty reduction programs, and building social capital in low-income communities in the course of entrepreneurial venturing.
 
 

3D Printed Lab-on-a-Chip Platform for Chemical Stimulation and Parallel Analysis of Ion Channel Function.

Functional imaging has been a widely established method for the assessment of ion channel function in vitro. Conventional infrastructure used for in vitro functional analysis of ion channels is typically proprietary, non-customizable, expensive, and requires a high level of skill to use and maintain. 3D desktop printing, which is employed in the rapid prototyping field, allows for quick engineering of alternatives to conventional imaging infrastructure that are customizable, low cost, and user friendly. Here, we describe an ultra-low-cost microfluidic lab-on-a-chip (LOC) device manufactured using acrylonitrile butadiene styrene (ABS) for in vitro functional imaging of ion channels that can quickly and easily be reconstructed using three-dimensional (3D) desktop printing. The device is light weight (<5 g), small (20 mm × 49 mm), and extremely low cost (<EUR 1). We simulate fluidics within the printed channels and assess the suitability of the engineered chamber to generate homogeneous mixtures during solution exchange. We demonstrate the usability of the 3D printed microfluidic device in a case study using Fluo-4-loaded human embryonal kidney-derived (HEK293) cells, recombinantly expressing the capsaicin receptor, transient receptor potential vanilloid receptor type 1 (TRPV1), as a model system. In the case study, we confirm its applicability to solution exchange for chemical stimulation and parallel functional time-lapse fluorescence microscopy-based calcium imaging. We assess the suitability of ABS for culturing HEK293 cells inside the microfluidic LOC, based on qualitative analysis of microscopic transmission light images of ABS-exposed HEK293 cells and confirm the previously reported biocompatibility of ABS. To highlight the versatility of the 3D printed microfluidic device, we provide an example for multiplication of the shown concept within a 3D printed multichannel microfluidic LOC to be used, for example, in a higher throughput format for parallelized functional analysis of ion channels. While this work focusses on Ca2+ imaging with TRPV1 channels, the device may also be useful for application with other ion channel types and in vitro models.

Classification of challenges in 3D printing for combined electrochemical and microfluidic applications: a review

PurposeThe purpose of this paper is to describe, review, classify and analyze the current challenges in three-dimensional printing processes for combined electrochemical and microfluidic fabrication areas, which include printing devices and sensors in specified areas.Design/methodology/approachA systematic review of the literature focusing on existing challenges is carried out. Focused toward sensors and devices in electrochemical and microfluidic areas, the challenges are oriented for a discussion exploring the suitability of printing varied geometries in an accurate manner. Classifications on challenges are based on four key categories such as process, material, size and application as the printer designs are mostly based on these parameters.FindingsA key three-dimensional printing process methodologies have their unique advantages compared to conventional printing methods, still having the challenges to be addressed, in terms of parameters such as cost, performance, speed, quality, accuracy and resolution. Three-dimensional printing is yet to be applied for consumer usable products, which will boost the manufacturing sector. To be specific, the resolution of printing in desktop printers needs improvement. Printing scientific products are halted with prototyping stages. Challenges in three-dimensional printing sensors and devices have to be addressed by forming integrated processes.Research limitations/implicationsThe research is underway to define an integrated process-based on three-dimensional Printing. The detailed technical details are not shared for scientific output. The literature is focused to define the challenges.Practical implicationsThe research can provide ideas to business on innovative designs. Research studies have scope for improvement ideas.Social implicationsReview is focused on to have an integrated three-dimensional printer combining processes. This is a cost-oriented approach saving much of space reducing complexity.Originality/valueTo date, no other publication reviews the varied three-dimensional printing challenges by classifying according to process, material, size and application aspects. Study on resolution based data is performed and analyzed for improvements. Addressing the challenges will be the solution to identify an integrated process methodology with a cost-effective approach for printing macro/micro/nano objects and devices.

Effective Usage of Information and Communications Technology by Career Administrators in Tertiary Institutions: The Obafemi Awolowo University Experience

The study identified the information and communication technology tools used by career administrators in Obafemi Awolowo University, Ile-Ife; determined the level of ICT compliance in the performance of administrative tasks by the career administrators in the said institution; examined the attitude of the respondents to the adoption and use of information and communication technologies in performing administrative tasks; and identified the challenges militating against the optimum deployment of information and communication technologies by career administrators in the institution under reference. These were with the view to understanding the use of information and communication technologies by professional or career Administrators in the study area. Both primary and secondary data sources of data collection were employed for the study. The former were obtained through a structured questionnaire and complemented by an interview guide. Out of a study population of 109, 85 respondents were selected by a simple random technique. Secondary data were obtained from relevant university books and digests, previously published and unpublished studies related to the use of ICT in different sectors of national life, official documents and internet sources on ICT. Data collected were analyzed using simple percentages. The study showed that access to basic ICT hardware such as desktop computers (85.8%) and printers (77.6%) in the workplace was fairly adequate, though, usage had to be negotiated in some instances. 92.9% of the respondents were able to use Microsoft Word and 5% were able to use Microsoft Access, while only 1.2% each were able to deploy the use of Prezi and Evernote in providing administrative services. The study also revealed that the major challenges militating against the maximal deployment of ICT tools by the respondents are epileptic power supply, unstable internet connectivity and the need to have to negotiate with other users of ICT hardware such as desktop, laptops and scanners in the workplace, before gaining access to such tools. The study concluded that information and communication technologies have been widely embraced by career Administrators in the University and this has to a large extent improved effectiveness, accuracy and efficiency in the area of service delivery. However, there was need for further training especially with regards to the use of some software with advanced features in Microsoft Word as well as Power Point, Prezi, Evernote, and Microsoft Access for improved administrative services in the University. Keywords: Information and Communications Technology; Higher Education Administration, Career Administrators, Prezi, Evernote DOI : 10.7176/JESD/10-16-21 Publication date : August 31 st 2019

Three-Dimensional Printed Polylactic Acid Scaffolds Promote Bone-like Matrix Deposition in Vitro.

Large bone defects represent a significant challenge for clinicians and surgeons. Tissue engineering for bone regeneration represents an innovative solution for this dilemma and may yield attractive alternate bone substitutes. Three-dimensional (3D) printing with inexpensive desktop printers shows promise in generating high-resolution structures mimicking native tissues using biocompatible, biodegradable, and cost-effective thermoplastics, which are already FDA-approved for food use, drug delivery, and many medical devices. Microporous 3D-printed polylactic acid scaffolds, with different pore sizes (500, 750, and 1000 μm), were designed and manufactured using an inexpensive desktop 3D printer, and the mechanical properties were assessed. The scaffolds were compared for cell growth, activity, and bone-like tissue formation using primary human osteoblasts. Osteoblasts showed high proliferation, metabolic activity, and osteogenic matrix protein production, in which 750 μm pore-size scaffolds showed superiority. Further experimentation using human mesenchymal stem cells on 750 μm pore scaffolds showed their ability in supporting osteogenic differentiation. These findings suggest that even in the absence of any surface modifications, low-cost 750 μm pore-size 3D-printed scaffolds may be suitable as a bone substitute for repair of large bone defects.

Particle Emissions from Laser Printers: Have They Decreased?

Our work a decade ago demonstrated that approximately 30% of the laser printers tested were high emitters of ultrafine particles (<0.1 μm). To assess how emission levels of the current generation of printers compared to the earlier models, we investigated 297 printers comprising 138 models from 12 different manufacturers, with the measurements conducted in Brisbane, Australia, and Cassino, Italy. In addition to particle number (PN—the majority of which are ultrafine particles), some of the printers were also tested for the emissions of volatile organic compounds (VOC). Based on the ratios of, respectively, PN and VOC concentrations above the printer before and after test printing, the printers were divided into four classes of emitters: nonemitters and low, medium, and high emitters. Our study showed that although different printer models were investigated in Brisbane and in Cassino, the distributions according to emitter classes were similar for PN emissions, with a high percentage of nonemitters and low PN emitters. In Brisbane, there were also mainly nonemitters and low VOC emitters, with, however, a higher percentage of VOC than PN emitters. In general we found that the emission levels were not intrinsic characteristics of specific brands or models of the printers. Finally, compared to the situation before 2007, large commercial printers have improved in terms of particle emissions; however, there has not been an obvious improvement over desktop printers.

Portoporator©: A portable low-cost electroporation device for gene transfer to cultured cells in biotechnology, biomedical research and education

Electroporation has been a widely established method for delivering DNA and other material into cells in vitro. Conventional electroporation infrastructure is typically immobile, non-customizable, non-transparent regarding the characteristics of output pulses, and expensive. Here, we describe a portable electroporator for DNA delivery into bacterial cells that can quickly be reconstructed using 3D desktop printing and off-the-shelf components. The device is light weight (700 g), small (70 × 180 × 210 mm) and extremely low-cost (<EUR 130). We provide the electrical circuitry and a detailed parts list for rebuilding the device. We characterize the properties of generated pulses and apply the system for gene delivery into bacterial Dh5α cells. We analyze the transformation efficiency based on the optical density of cell suspensions at 595 nm and on quantitative analysis of images obtained from bacterial cell-grown agar plates using colony forming units as well as confluence as indicators. We demonstrate time-dependency of the transformation efficiency using single pulses of 500 V between 1 and 1000 ms duration and we show that commercially available electroporation cuvettes of 1 mm gap size reveal higher transformation rates compared to cuvettes with 2 mm gap. We benchmark the transformation efficiency obtained using our platform with data from a heat shock-based transformation protocol and with data from a commercially available electroporator and show that our system reveals comparable results as the other techniques in the applied configurations. While this work focuses on genetic manipulation of bacterial cells, the device may also be applicable for delivery of genetic material small molecule or nanomaterials into other cell types, including mammalian cells.

High-Precision Stereolithography of Biomicrofluidic Devices.

Stereolithography (SL) is emerging as an attractive alternative to soft lithography for fabricating microfluidic devices due to its low cost and high design efficiency. Low molecular weight poly(ethylene glycol)diacrylate (MW = 258) (PEG-DA-258) has been used for SL 3D-printing of biocompatible microdevices at submillimeter resolution. However, 3D-printing resins that simultaneously feature high transparency, high biocompatibility, and high resolution are still lacking. It is found that photosensitizer isopropyl thioxanthone can, in a concentration-dependent manner, increase the absorbance of the resin (containing PEG-DA-258 and photoinitator Irgacure-819) by over an order of magnitude. This increase in absorbance allows for SL printing of microdevices at sub pixel resolution with commercially available desktop printers and without compromising transparency or biocompatibility. The assembly-free, rapid (<15 h) 3D-printing of a variety of complex 3D microfluidic devices such as a 3D-fluid router, a passive chaotic micro-mixer, an active micro-mixer with pneumatic microvalves, and high-aspect ratio (37:1) microchannels of single pixel width is demonstrated. These manufacturing capabilities are unavailable in conventional microfluidic rapid prototyping techniques. The low absorption of small hydrophobic molecules and microfluidic labeling of cultured mammalian cells in 3D-printed PEG-DA-258 microdevices is demonstrated, indicating the potential of PEG-DA-based fabrication of cell-based assays, drug discovery, and organ-on-chip platforms.

3D printing for chemical, pharmaceutical and biological applications

3D printing is becoming increasingly prevalent in modern chemistry laboratories. This technology provides chemists with the ability to design, prototype and print functional devices that integrate catalytic and/or analytical functionalities and even to print common laboratory hardware and teaching aids. Although access to 3D printers has increased considerably, some design principles and material considerations need to be weighed before employing such technology in chemistry laboratories. In addition, a certain level of expertise needs to be acquired in order to use computer-aided design, printing software and the specialist hardware associated with higher-end instrumentation. Nonetheless, the recent progress in this field is encouraging, with these printing technologies offering many advantages over traditional production methods. This Review highlights some of the notable advances in this growing area over the past decade. 3D printing is becoming a mainstream technology with considerable increase in access to affordable desktop printers. However, specific design principles and material considerations need to be weighed when printing functional devices that integrate catalytic and/or analytical functionalities, as well as when printing common laboratory hardware.

Development and Application of a No-Clog Surgical Suction Tip Using 3D Printing Technology.

BackgroundClogging of the suction tip frequently occurs during orthopedic surgery. We developed a novel anti-clog suction tip using 3D printing technology to improve orthopedic surgery efficiency.Material/MethodsWe studied the root causes of obstructions in suction tips currently employed in orthopedic surgery during actual surgical cases. CAD software and 3D printer was used to design, modify, and print the novel suction tip. The frequency of clogging, the frequency of replacement of the suction tip, the time lost in replacing suction tips or connecting tubes, surgical duration, intraoperative surgical blood loss, and the satisfaction scores for the suction tips as rated by the surgeons were compared between the novel suction tip and the conventional suction tip. Comparisons were made first in laboratory experiments using a simulant liquid and then during total hip replacement surgeries.ResultsIn the simulant liquid experiments, the novel suction tips showed significantly reduced frequency of complete clogging and decreased time spent removing all fluid in comparison to the conventional suction tips (p<0.05). In the clinical trials, the novel suction tips exhibited significantly reduced frequency of complete clogging, shorter surgical duration, and reduced intraoperative surgical blood loss compared to the conventional suction tips (p<0.05). Surgeon satisfaction scores were higher for the novel tips than for the conventional tips (p<0.05).ConclusionsOur surgeon-designed and -produced surgical suction tip utilizing 3D desktop printing technology was highly effective in resolving the problem of clogged suction tips during orthopedic surgery and yielded high surgeon satisfaction.

Kinematic error modeling and error compensation of desktop 3D printer

Desktop 3D printers have revolutionized how designers and makers prototype and manufacture certain products. Highly popular fuse deposition modeling (FDM) desktop printers have enabled a shift to low-cost consumer goods markets, through reduced capital equipment investment and consumable material costs. However, with this drive to reduce costs, the computer numerical control (CNC) systems implemented in FDM printers are often compromised by poor accuracy and contouring errors. This condition is most critical as users begin to use 3D-printed components in load-bearing applications or to perform mechanical functions. Improved methods of low-cost 3D printer calibration are needed before their open-design potential can be realized in applications, including 3D-printed orthotics and prosthetics. This paper applies methodologies associated with high-precision CNC machining systems, namely, kinematic error modeling and compensation coupled with standardized test methods from ISO230-4, such as the ballbar for kinematic and dynamic error measurements, to examine the influence and feasibility for use on low-cost CNC/3D printing platforms. Recently, the U.S. Food and Drug Administration’s “Technical considerations for additive manufactured medical devices” highlighted the need to develop standards specific to additive manufacturing in regulated manufacturing environments. This paper shows the benefits of the methods described within ISO230-4 for error assessment, alongside applying kinematic error modeling and compensation to the popular kinematic configuration of an Ultimaker 3D printer. A Renishaw ballbar QC10 is used to quantify the Ultimaker’s errors and thereby populate the error model. This method quantifies machine errors and populates these in a mathematical model of the CNC system. Then, a post-processor can be used to compensate the printing code. Subsequently, the ballbar is used to demonstrate the dramatic impact of the error compensation model on the accuracy and contouring of the Ultimaker printer with 58% reduction in overall circularity error and 90% reduction in squareness error.

3D Printed Surgical Simulation Models as educational tool by maxillofacial surgeons.

The aim of this study was to evaluate whether inexpensive 3D models can be suitable to train surgical skills to dental students or oral and maxillofacial surgery residents. Furthermore, we wanted to know which of the most common filament materials, acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), can better simulate human bone according to surgeons' subjective perceptions. Upper and lower jaw models were produced with common 3D desktop printers, ABS and PLA filament and silicon rubber for soft tissue simulation. Those models were given to 10 blinded, experienced maxillofacial surgeons to perform sinus lift and wisdom teeth extraction. Evaluation was made using a questionnaire. Because of slightly different density and filament prices, each silicon-covered model costs between 1.40-1.60 USD (ABS) and 1.80-2.00 USD (PLA) based on 2017 material costs. Ten experienced raters took part in the study. All raters deemed the models suitable for surgical education. No significant differences between ABS and PLA were found, with both having distinct advantages. The study demonstrated that 3D printing with inexpensive printing filaments is a promising method for training oral and maxillofacial surgery residents or dental students in selected surgical procedures. With a simple and cost-efficient manufacturing process, models of actual patient cases can be produced on a small scale, simulating many kinds of surgical procedures.

Dual-objective Analysis for Desktop FDM Printers: Energy Consumption and Surface Roughness

FDM printing has become familiar and close to the public. Considering its scale, the energy consumption of desktop FDM printers should be attended. Existing research, however, heavily focused on part quality, particularly, surface roughness. In this research, energy consumption and surface roughness were simultaneously considered. Full factorial experiments were designed and conducted, to 1) investigate the impact of key process parameters, including layer thickness, printing speed, and infill ratio, on the energy consumption and surface roughness using one desktop printer, and 2) compare the energy consumption and surface roughness of fabricated parts using a same set of parameters on three different printers. Dual-objective analysis was then performed. Layer thickness was identified as the most influential factor, generating opposite impact on the two objectives. The observed surfaces are relatively rough with uncertainties, such as spikes and wavy curves. It is, therefore, suggested that most desktop printers can be configured primarily for energy savings.

Accessing individual 75-micron diameter nozzles of a desktop inkjet printer to dispense picoliter droplets on demand.

Desktop inkjet printers are ubiquitous and relatively inexpensive among the variety of available printers. These inkjet printers use an array of micro fluidic pumps, nozzles based on piezoelectric actuation, to dispense individual picoliter volume ink droplets at high speed. In this paper, we show that individual pumps in desktop printers can be accessed to dispense droplets on demand. Access was obtained using the printer’s command language programming. A detailed description of the access procedure is discussed. Droplets were printed on a paper as it rolled underneath the printhead, and with a minor hardware modification, they were also printed on a glass substrate. With this access, individual droplets were deposited, the smallest having an average diameter of 62 μm with a standard deviation of 6.9 μm, with a volume of ∼4 pL. From the intended position, the droplets had a standard deviation of 5.4 μm and 8.4 μm in the vertical and horizontal directions, respectively. The ink droplets were dispensed at a rate of 7.1 kHz. A circularity factor of 0.86 was obtained indicating that the dispensed droplets are of good quality. By replacing the ink in the cartridges with liquids of choice (e.g. cells, proteins, nanoparticles etc.), we believe it provides an opportunity for low-cost, high-speed, high-precision, picoliter volume printing for a variety of applications.

Tuning inkjet printability of hydroxypropylated-starch-based coatings by mineral selection

Coatings based on hydroxypropylated starch (HPS) provide extraordinary print density with dye-based inkjet inks, but their suitability for pigment-based inks can be limited due to inadequate carrier medium (water) absorption and colorant fixation. In the present work, HPS-based coatings were tailored for both a pigmentbased and a dye-based ink by adding silicate minerals or acid clay (both Lewis and Br&#xF6;nstedt acid sites present in the acid clay). Substrate-ink interaction and colorant distribution were investigated via uncoated gloss and print quality indicators such as print density, ink bleeding tendency and delta gloss after printing with desktop printers. Three-dimensional z-stack CLSM images taken from printed samples revealed substantial differences in ink holdout and penetration characteristics between the studied materials. Pigment-filled HPS coatings showed up to 60% increase in print density compared to uncoated reference substrate and an increase of up to 35% compared to plain HPS coating with dyebased inks. In case of pigment-based ink, the increase was 17% between plain HPS coating and acid-clay-filled HPS coating. In addition, a combination of HPS and silicate mineral decreased ink bleeding substantially, but lower print gloss compared to substrate initial gloss was observed with the majority of experimental coatings. It was found that the pigment type affects substantially the unprinted gloss, which is naturally high in the case of pure HPS coating, but also the observed drastic difference in substrate permeability may explain the differences in print quality. The findings suggest that coating morphology, together with chemical interactions between starch and mineral and coated substrate and ink, has a key role in achieving high gloss and good print quality.

Three-Dimensional Printing of a Hemorrhagic Cervical Cancer Model for Postgraduate Gynecological Training.

IntroductionA realistic hemorrhagic cervical cancer model was three-dimensionally (3D) printed and used in a postgraduate medical simulation training session.Materials and methodsComputer-assisted design (CAD) software was the platform of choice to create and refine the cervical model. Once the prototype was finalized, another software allowed for the addition of a neoplastic mass, which included openings for bleeding from the neoplasm and cervical os. 3D printing was done using two desktop printers and three different materials. An emergency medicine simulation case was presented to obstetrics and gynecology residents who were at varying stages of their training. The scenario included history taking and physical examination of a standardized patient. This was a hybrid simulation; a synthetic pelvic task trainer that allowed the placement of the cervical model was connected to the standardized patient. The task trainer was placed under a drape and appeared to extend from the standardized patient’s body. At various points in the simulation, the standardized patient controlled the cervical bleeding through a peripheral venous line. Feedback forms were completed, and the models were discussed and evaluated with staff.ResultsA final cervical model was created and successfully printed. Overall, the models were reported to be similar to a real cervix. The models bled well. Most models were not sutured during the scenarios, but overall, the value of the printed cervical models was reported to be high.DiscussionThe models were well received, but it was suggested that more colors be integrated into the cervix in order to better emphasize the intended pathology. The model design requires further improvement, such as the addition of a locking mechanism, in order to ensure that the cervix stays inside the task trainer throughout the simulation. Adjustments to the simulated blood product would allow the bleeding to flow more vigorously. Additionally, a different simulation scenario might be more suitable to explore the residents’ ability to suture the cervical models, as cervical suturing of a neoplasm is not a common emergency department procedure.Conclusion3D-printed cervical models are an economical and anatomically accurate option for simulation training and other educational purposes.

Flexible RFID Tag Inductor Printed by Liquid Metal Ink Printer and Its Characterization

In order to fulfill various growing needs of application fields, the development of low-cost directly printable radio-frequency identification (RFID) tag is essential for item level tracking. Currently, there lacks an easily available way to directly write out functional consumer electronicslike typewriting on paper by an office printer. Here, we show a desktop printing of RFID tag inductors on flexible substrates via developing liquid metal ink and related working mechanisms. The directly printing inductor on various flexible substrates with extremely low cost and rapid speed was designed based on the sympathetic oscillations of multiple LC (inductor–capacitor) circuits. In order to better meet the demands of the distinct resonant circuits, a series of conceptual experiments for investigating the relationship between the character of the inductor and its parameters—shape, number of coils, line width, spacing, etc.,—have been designed. The parameters are all working upon the performance of the printed inductors by liquid metal ink printer, and the relationship laws are consistent with those of the conventional inductors. The coils number as the biggest effect factor has a linear relationship with the inductance of the spiral-type inductors. An inductor with excellent properties can be well chosen by adjusting its parameters according to various applications. The present work demonstrated the way for a low cost and easy going method in directly printing RFID tag inductors on flexible substrates.