Printed circuit boards have been massively manufactured and wildly used in all kinds of electronic devices during people’s daily life for more than thirty years since the last century. As a highly integrated device mainly consists of silicon base, an etched copper layer and other soldered components, massive production of printed circuit boards are considered to be environmentally unfriendly due to the wet chemical manufacturing mode and lack of recycling ability. On the other hand, the newly invented ink jet printing technology enables cost-effective manufacturing of flexible, thin and disposable electrical devices, which avoid acid etching process and lead to less toxic emissions into the environment. It is important to consider life cycle analysis for quantitative environmental impact evaluation and comparison of both printed circuit boards and printed electronics to enhance the sustainability of a new technology with product design and development. This thesis first reviews the current approaches to conventional and modern printing methods, as well as the state-of-the-art analysis of sustainability and environmental assessment methodologies. In the second part, a typical ink jet printed electronic device is introduced (an active flexible cable for wearable electrocardiogram monitoring). This active cable is designed for the interconnection between bio electrodes and central medical devices for bio signal transmission. As the active cable consists of five different metal transmission traces which are formed by printing conductive ink onto paper substrates, different shielding methods are investigated to ensure high quality bio signal transmission. Specifically, the results prove that passive shielding methods can significantly decrease the cross talk between different transmission traces, enabling the transmitting of bio signals for wearable ECG monitoring. This research also explores environmental issues related to printed electronics. For the full life cycle of printed electronics, we focused not only on quantitative environmental emissions to air, fresh water, sea and industrial soil, but also on resource consumption and impacts analysis. Finally, comparative environmental performance evaluation of traditional cables and ink jet printed active cables are made to examine the environmental impact and sustainability of both technologies, and the results show the strengths and weaknesses of each technology by analysis and assessment. / <p>QC 20171205</p>

Ligna Energy has developed a printable battery, called S-Power. It is based on research in organic electronics. In order to demonstrate the functionality of the new batteries, an IoT device was developed. The demonstrator consisted of a Sensor for temperature and relative humidity (RH), LoRWAN communication and a circuit for energy harvesting. Photovoltaic cells from Epishine were used in order to be able to harvest energy in low light conditions. At an illuminance of 200 lux, the demonstrator was able to sample the temperature and RH and send it by radio communication every two minutes. If no light at all is available, the demonstrator can sample data and send it every 30 minutes for over 12 hours. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

OBJECTIVES: The objective was to investigate the accuracy, storage stability, and mechanical properties of 3D-printed polymeric dental materials. MATERIALS AND METHODS: Three completely dentate models, two maxillary and one mandibular each with their respective die, and three implant models were designed using dental CAD software (3SHAPE DENTAL SYSTEM). A horseshoe-shaped solid base with a posterior horizontal bar was utilized. The models were printed based on the manufacturer's instructions for four weeks using six printers with the corresponding recommended resin materials: Carbon M2 (DPR10), HeyGears A2D4K (Model HP UV2.0), Stratasys J5 (MED610), Stratasys Origin One (DM200), Envision One (E-Model LightDLP), and Asiga Pro4K (VeriModel) with a standard layer thickness of 50 μm (N=72). The models were scanned after printing using Sirona inEOS X5 scanner, while the implant models were scanned using a CT scanner (GE Phoenix V|tome|x metrology edition). The full arch models were randomly assigned to three groups of storage conditions: cold environment (LT, 4 ± 1°C), hot and dry environment (HT, 50 ± 2°C), and room temperature (RT , 25 ± 2°C, serving as the control). Each group was kept under the designated conditions and scanned at 1, 2, 3, 4, and 8 weeks. The generated STL files were imported into a 3D inspection software for comparison with the original STL files. Four sets of reference points (central fossa of first premolars and central fossae of second molars) were selected to determine six distances of inter-arch segments, from which the inter-arch distance trueness and precision deviation were measured. For the second part of the study, maxillary Lucitone Digital Print denture base (DB) (N=5), maxillary Lucitone IPN 3D Premium anterior and posterior teeth (N=6), and maxillary Keystone Keysplint Soft Clear occlusal splint (N=5) were printed using two printers (Carbon M2, Asiga Max UV) with a standard layer thickness of 50 μm for denture base and teeth, and 100 μm for the occlusal splint. The tolerance threshold was set to 50 μm for Lucitone IPN and 100 μm for Lucitone DB and Keysplint Soft. In-tolerance percentage and deviation RMS were obtained and analyzed with multivariate least square mean linear regression using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05). The third part investigated the mechanical properties of Lucitone DB and IPN using 2 printers (Carbon M2, Asiga Max UV) as follows: flexural strength (N=10) using a threepoint bend test, fracture toughness (N=10), creep (N=5), Vickers hardness test (N=15), surface roughness (N=15), while Shore A hardness (N=15) and tensile strength (N=10) were performed for Keysplint Soft Clear. Data were analyzed using one-way and multivariate least square mean linear regression followed by Tukey’s HSD test using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05). RESULTS: The in-tolerance percentage varied significantly among printers, with Carbon M2 (CAB) showing the highest values. Stratasys (J5) displayed the highest accuracy in term of precision, while HeyGears A2D4K (HGS), Carbon M2 (CAB), and Stratasys (J5) exhibited the highest accuracy in term of trueness. The inter-molar segment showed the highest deviation. No significant difference was observed in in-tolerance percentage across different print weeks except for week 2 in one printer (Stratasys Origin1). CAB exhibited a higher in-tolerance percentage for the DB than Asiga Max UV (ASG), with the fitting surface having the highest in-tolerance percentage. IPN anterior teeth had a higher intolerance percentage than posterior teeth, with ASG showing a higher value than CAB. No statistically significant difference was found in the in-tolerance percentage of Keysplint Soft Clear between ASG and CAB. Resin printed using ASG demonstrated higher flexural strength, Vickers hardness, and creep, while resin printer using CAB exhibited higher fracture toughness, with no significant difference in surface roughness between the two printers. Lucitone IPN had higher flexural strength and Vickers hardness, surface roughness , and lower creep and fracture toughness than Lucitone DB. CAB Keysplint Soft had higher tensile strength than ASG, with no statistically significant difference in Shore A hardness between the two printers. CONCLUSION: Model dimension deviations were impacted by storage conditions and the specific printer utilized, with high-temperature storage exhibiting the least stability. However, no significant difference was noted between low and room temperature storage conditions. Carbon M2 exhibited the highest level of accuracy. The of 3D-printed denture bases and denture teeth varied across different printers. Conversely, no significant difference in accuracy was observed for a soft occlusal splint between two printers. Materials printed using different printers showed statistically significant different mechanical properties.

Motor vehicle crashes are the leading cause of unintentional injury-related death among children ages 14 and under and of these children who were fatally injured more that 60 % were not using safety restraints at the time of the collision. Children who are too large for child safety seats are often restrained improperly or not at all. In addition, many children are being shifted from child safety seats to adult safety belts prematurely. For proper protection, children who have outgrown child safety seats require booster seats combined with vehicle lap/shoulder belts. A booster seat raises a child up so that the lap and shoulder belts fit properly. The current research went through a systematic approach, from several perspectives, to develop an effective pamphlet to increase behavioral compliance of purchasing a booster seat. The pamphlet developed throughout these studies had a substantial and positive effect on intention and perceived control as well as a meaningful and substantial impact on actual purchase behavior. In addition, the associated guidelines that were developed allow others to produce effective printed educational materials. This research consisted of five studies described below. Study 1 consisted of 43 subject matter experts who were used to determine pertinent information that should be included in a complete booster seat pamphlet. Nine of the 20 items showed significance and were included in the first iteration of the pamphlet. Study 2 consisted of 5 parents of children who should be in booster seats and were not at the time of the study, evaluated the usability of the first iteration pamphlet. A total of 18 items were changed in the pamphlet and a subsequent second iteration of the pamphlet was developed. Study 3 consisted of 30 parents of children who should be in booster seats and were not at the time of the study, were used to assess the comprehensibility (Cloze test), hazard-risk judgments (carefulness ratings), and understandability (questionnaire) of three booster seat pamphlets. Significance was found for the second iteration pamphlet in both comprehensibility and understandability, but no significance was found in risk perception. Study 4 consisted of 8 human factors graduate students who were used to assess the reading level (SMOG test), instructional design and inclusion of learning principles (BIDS-3 test), and readability (RAINS test) of three booster seat pamphlets. The second iteration pamphlet and two existing industry pamphlets were used in Studies 3 and 4 and significance was found for the second iteration pamphlet in both instructional design and learning principles as well as readability and was the only pamphlet to have a reading level under 8th grade. Subsequent to these studies a third iteration of the new pamphlet was developed. Study 5 consisted of 45 parents of children who should be in booster seats and were not at the time of the study. Three booster seat pamphlets, two from the child passenger safety industry and the third iteration pamphlet were used as treatments (15 participants per group). Effectiveness of the intervention was tested by assessing three variables, intent to purchase (revealed that when intent was high purchase was high), perceived control of purchasing (revealed that when perceived control was high purchase was high), and actual purchase behavior (third iteration pamphlet showed a significantly higher purchase rate than the industry pamphlets). Of the 19 participants who purchased a booster seat, there were 12 (63%) in the third iteration pamphlet group, 2 (11%) in the alternate 1 pamphlet group, and 5 (26%) in the alternate 2 pamphlet group, and 100% of those who purchased, reported that they use them each time their child rides in a vehicle. This research increased our understanding of information design and well as generating general design guidelines for pamphlets. In addition, this research produced a pamphlet for credible sources to use as an education tool for parents who have children who should be in booster seats and are not placed in them when riding in a vehicle. / Ph. D.

In this work, we sought to provide a deeper understanding of the energy-absorbing capabilities of cast lattice structures. These structures absorb large amounts of energy via plastic deformation, but their most attractive characteristic from a structural standpoint is the favorable energy absorption-to-weight ratio. Conventional machining techniques are not well suited for manufacturing such complex features; therefore, we combined additive manufacturing (AM) with a well-known understanding of the metalcasting process. We used AM to produce sand molds in different sizes and with additional features for various applications — these molds were then filled with molten metal. Current literature suggests that this when appropriately applied, this methodology results in complex geometries castings comparable properties to parts made with traditionally produced sand molds. We chose to study periodic lattice structures for their repeatability and subsequent ease of making predictions via computer simulations. We first produced lightweight cast metal-ceramic composite panels of 225 x 225 x 60 mm. Our AM molds included provisions to install ceramic or hard metal tiles before pouring the molten metal. The tiles were encapsulated in the final casting to yield a composite structure. The initial material selection consisted of an aluminum A356-T6 alloy matrix with silicon carbide tiles. The composite lattice structures were tested against high-velocity projectiles — 0.30 caliber armor-piercing (AP M2) and NATO 7.62 mm ball rounds. We anticipated that the metal matrix alone would not be able to defeat these threats. However, the panels did reduce the striking velocity by approximately 20%. The thickness of the ceramic tiles varied from 4 mm to 8 mm at 2 mm increments. As expected, the hard ceramic tiles proved effective at improving the penetration resistance of the composite lattice structures — the impacts on regions with 4 mm thick tiles resulted in the reduction of striking velocity up to 49%; moreover, as the thickness was increased to 8 mm, the panels defeated the projectiles. We used these results to produce and validate a finite element (FE) model capable of replicating the experimental data within 5%. This model was later used to study how the ceramic material interacts with the lattice to absorb large amounts of kinetic energy from incident projectiles. Following, we manufactured smaller versions of these panels—50 x 50 x 90 mm test specimens for uniaxial compression testing for this instance. Once again, we relied on the capabilities of the FE method to replicate the test results within 10% for peak load and maximum displacement. We utilized computer simulations to optimize the design of the lattice structure. Its energy-absorbing capabilities were improved significantly — in this case, a 30% increase in the specific internal energy (internal energy per unit mass) as the evaluating criteria. The FE model was also used to study the performance of several other truss topologies. Lastly, we used computer simulations to evaluate the feasibility of making these cast lattice structures with ferrous alloys. We chose to work with Fe30Mn4Al0.9C due to its lower density and higher toughness than other steel grades. The first challenge was the lack of thermophysical property data in the literature for this alloy system. Hence, we used the CALPHAD method to calculate all the datasets needed to perform the mold filling and solidification simulation. Several of these calculations were validated experimentally. The location and severity of porosity between the model and the casting were in good agreement. / Doctor of Philosophy / The advent of additive manufacturing (AM), commonly known as 3D printing is a group of different digital-era technologies that has facilitated the production of complex designs that are not feasible to manufacture using conventional techniques. In the realm of metallic components one such technique involves the use of a laser beam to consolidate metallic powders via a layer-by-layer deposition process. Despite its advantages, this process has unique challenges, such as limited material selection and relatively small part volume. In this work, we have employed a hybrid approach that combines the use of AM with expertise in metalcasting to produce lightweight components with complex geometries. We used 3D printed sand molds that are then filled with molten metal of different alloy systems such as aluminum and steel. At first, we incorporate hard ceramic materials to increase the performance of the final parts under ballistics testing. Our aim is to upscale the size of current designs such that these devices can be used in various applications that require high absorption of kinetic energy, and that are lightweight and easy to replace.

The focus of this research is the line assignment problem in printed circuit card assembly systems. The line assignment problem involves the allocation of circuit card types to an appropriate assembly line among a set of assembly lines with the objective of reducing the total assembly time. These circuit cards are to be assembled in a manufacturing facility, capable of simultaneously producing a wide variety of printed circuit cards in different production volumes. A set of component types is required for each printed circuit card. The objective is to assign the circuit cards to the assembly line such that the total assembly time, which includes the setup time as well as the processing time required for all card types in a set, is minimized. The focus of this research is to develop an algorithmic strategy for addressing this problem in electronics assembly. This problem involves considering several interrelated decision problems such as assigning printed circuit cards to assembly lines, grouping circuit cards into families to reduce the number of setups, and assigning component types to machines to balance workload. The line assignment models are formulated as large scale mixed integer programming problems and are solved using a branch-and-bound algorithm, supplemented by techniques for improving the solution time. The models and solution approaches are demonstrated using industry representative data sets and can serve as useful decision support tools for process planning engineers. / Master of Science

Large format 3D printing of thermoplastic polymers is a fast growing technology for industrial tools manufacturing and enables the production of meters long workpiece in a fraction of time, material and cost than conventional subtractive solutions. Due to the scale and timing imposed by the industry, Large Format Additive Manufacturing (LFAM) is mostly based on screw extrusion of thermoplastic pellets offering a significantly higher deposition rate and lower material costs compared to the well-known filament extrusion 3D printing (FFF). Carbon fiber reinforced polymers are commonly used in large-scale 3D printing as they minimize distortions and internal stresses during deposition preventing delamination and failure of the printed component. The technology stands out for the exceptional melt deposition rate; the lack of a temperature-controlled build chamber, and the low surface-to-volume proportion of the printed strand, making the temperature management of the deposited material particularly challenging in large-scale 3D printing. Print overcooling may lead to poor adhesion between layers eventually resulting in delamination, excessive heat build-up, on the other hand, is likely to result in sagging and print failure. Print thermal behavior and temperature management are closely related to material, part design and deposition strategy. Even though numerous software solutions for predictive process simulation as well as active feedback print controls for parameters optimization are emerging, common practice still relies on restricted set of strategies deduced by trial and error testing sessions; the best printing configuration is specifically custom-made for each print, an approach that could severely hinder the technology potential. This research is conducted as part of the project of CMS S.p.a., a company specialized in the production of CNC multi-axis machining centers, to develop and market an all-around tool manufacturing solution that would combine milling and Screw Extrusion Additive Manufacturing (SEAM). The study aims to develop a flexible and versatile cooling model that can predict the best process window for large-scale additive manufactured parts and automatically generate the best printing parameters for a generic printing strategy according to part material and shape. Next, the model was incorporated inside a path generation slicing software that operates with the same process parameters, unique solution on the market. Any given material is described by a specific set of variables that can be experimentally derived using a simple standardized procedure. Four industrially relevant materials were investigated for thermal model and software validation. In the framework of large format 3D printed tool manufacturing, 40 wt% carbon fiber reinforced polyamide 6 (PA6) and 20 wt% carbon fiber reinforced acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), and polyetherimide (PEI) play a strategic role in most applications. In addition, the research offers a physical, mechanical and thermal characterization of the printed workpiece providing a comprehensive guideline for part design, arrangement, and thermal compensation for traditional CFRP manufacturing tools. Finally, for each material, a real tool manufacturing case study and post-processed surface qualification is presented.

In order to function safely in a dynamic environment with humans and obstacles, robots require active compliance control with force feedback. In these applications the control law typically includes full dynamics compensation to decouple the joints and cancel out nonlinearities, for which a high-fidelity model of the robot is required. In the case of a 3D-printed robot, components cannot be easily modeled due non-uniform densities, inconsistencies among the 3D printers used in manufacturing, and the use of different plastics with mechanical properties that are not widely known. To address this issue, this thesis presents an adaptive control framework which modifies the model parameters online in order to achieve satisfactory tracking performance. The inertial properties are estimated by adapting with respect to functions of the unknown parameters. This is achieved by rewriting the robot dynamics equations as the product of a matrix of known nonlinear functions of the joint states and a vector of constant unknowns. The result is a nonlinear system linearly parameterized in terms of the of the unknowns, which can be estimated using adaptation laws derived from Lyapunov stability theory. The proposed control system consists of an outer-loop impedance controller to regulate deviations from the nominal trajectory in the presence of disturbances, and an inner-loop force controller to track the joint torques commanded by the outer-loop. The proposed system is evaluated on an early prototype consisting of a 3DOF leg, and two actuator test setups for the low-level controller. / Master of Science / In order to function safely in a dynamic environment with humans and obstacles, a robot must be able to actively control its interaction forces with the outside environment. In these applications a high-fidelity model of the robot is required. In the case of a 3D-printed robot, the components in the robot cannot be easily modeled due non-uniform densities, inconsistencies among the 3D printers used in manufacturing, and the use of different plastics with mechanical properties that are not widely known. To address this issue, this thesis presents an adaptive control framework which actively modifies the model parameters in order to achieve satisfactory tracking performance. In this work, the equations of motion of the robot are manipulated in such a way that the unknown quantities are separated from the known quantities. The unknowns are updated in real time using adaptive laws derived from Lyapunov stability theory. The proposed control system consists of a high-level torque controller to regulate deviations from the nominal trajectory, and a low-level force controller to track the joint torques commanded at the high-level. The proposed system is evaluated on an early prototype of the robot consisting of a 3 degree of freedom leg, and two actuator test setups for the low-level controller.

The hybridization of direct write (DW) and additive manufacturing (AM) technologies to create additively manufactured electronics (AME) has enabled the integration of electrical functionality to form multifunctional AM components. Current work in AME has demonstrated the integration of conductive traces into and onto geometries and form factors that are not possible through traditional electronics packaging processes. This has largely been accomplished by using AM and DW technology to deposit conductive inks to form interconnects on the surface of AM substrates or within multimaterial AM geometries. However, the requisite thermal post-processing and high resistivity of the conductive inks and the limitations in thermal and dielectric performance of printable substrates commonly used in AME restrict the capabilities of these parts. This thesis proposes an alternative process for the conformal deposition of low resistivity traces on additively manufactured all-aromatic polyimides (AM-PI) without the use of conductive inks. This is accomplished through the selective patterning of laser induced graphene (LIG), a porous 3D graphene fabricated via laser irradiation, onto the AM-PI. While the resultant LIG is conductive, its resistivity is further reduced by the electrodeposition of copper (Cu-LIG). In this thesis, the synthesis of LIG on AM-PI, thermally post processed to 240℃, 300℃, and 450℃, is demonstrated and characterized through sheet resistance measurements and Raman spectroscopy. AM-PI post-processed to 300℃ demonstrated the lowest resistivity LIG formation (13.8 Ω/square). The resistivity of Cu-LIG is compared to an industry standard silver ink (Micromax CB028) used in direct write hybrid manufacturing applications. Cu-LIG was found to have a measured resistivity (1.39e-7 Ω·m), two orders of magnitude lower than the measured resistivity of the CB028 silver ink (1.62e-5 Ω·m). Additionally, the current capacity of the Cu-LIG was demonstrated and Joule heating of the material was observed via IR thermography. Cu-LIG demonstrated no failure of conductive trace or substrate under 5A of current for 2 minutes, heating to a maximum recorded temperature of 76.3℃. Several multifunctional components were fabricated as case studies to further validate the process. Several small passive electronic devices (e.g., a heater and an interdigitated capacitor) are fabricated to demonstrate selective deposition of complex copper traces. The fabrication of an Archimedes spiral on a hemispherical substrate via Cu-LIG is completed to demonstrate the ability to use the process to fabricate conformal conductive traces. An LED circuit is fabricated on a face-center cubic AM-PI lattice which demonstrates multi-planar fabrication on geometrically complex 3D printed substrates. / Master of Science / The hybridization of direct write (DW) and additive manufacturing (AM) technologies to create additively manufactured electronics (AME) has enabled the fabrication of AM components which have electronic functionality. Current work in AME has demonstrated the integration of conductive traces into and onto geometries and form factors that are not possible through traditional electronics packaging processes. This has largely been accomplished through the deposition of conductive inks to form interconnects on the surface of AM substrates or within multimaterial AM geometries. However, these conductive inks require thermal post-processing temperatures which exceed the thermal performance of common AM substrates. The dielectric performance of AM substrates is also restrictive to the capabilities of these parts. This thesis proposes an alternative process for the conformal deposition of low resistivity traces on high performance additively manufactured all-aromatic polyimides (AM-PI) without the use of conductive inks. This is accomplished through the selective patterning of laser induced graphene (LIG), a porous 3D graphene fabricated via laser irradiation, onto the AM-PI. While the resultant LIG is conductive, its resistivity is further reduced by the electrodeposition of copper (Cu-LIG). In this thesis, the synthesis of LIG on AM-PI, thermally post processed to 240℃, 300℃, and 450℃, is demonstrated and characterized through sheet resistance measurements and Raman spectroscopy. AM-PI post-processed to 300℃ demonstrated the lowest sheet resistance LIG formation (13.8 Ω/square). The resistivity of Cu-LIG is compared to an industry standard silver ink (Micromax CB028) used in direct write hybrid manufacturing applications. Cu-LIG was found to have a measured resistivity (1.39e-7 Ω·m), two orders of magnitude lower than the measured resistivity of the CB028 silver ink (1.62e-5 Ω·m). Additionally, the thermal performance and current capacity of the Cu-LIG was demonstrated by observing resistive heating of the material under current load via IR thermography. Cu-LIG demonstrated no failure of conductive trace or substrate under 5A of current for 2 minutes, heating to a maximum recorded temperature of 76.3℃. Several multifunctional components were fabricated as case studies to further validate the process. A heater and an interdigitated capacitor are fabricated to demonstrate selective deposition of complex copper traces. The fabrication of an Archimedes spiral on a dome via Cu-LIG is completed to demonstrate the ability to use the process to fabricate conformal conductive traces. An LED circuit is fabricated on an AM-PI lattice which demonstrates multi-planar fabrication on geometrically complex 3D printed substrates.

My dissertation studies gender and politics in printed imagetexts in colonial Bengal. It covers the period from the publication of the Bengali Punch Magazine, Basantak, in 1874 to the circulation of anti-imperial newspaper gags during WWII. At the core of this project are colonial illustrated periodicals—the quintessential mediums of colonial modernity and pedagogy, and the bearer of anticolonial imagetexts. The dissertation analyzes printed imagetexts like comics, cartoons, caricatures, newspaper gags, posters, and advertisements in periodicals and their effects on anti-imperial thought and the politicization of colonial popular culture. Imagetexts are synthetic mediums where ‘image’ and ‘text’ compositely create meaning. I argue that the printed imagetexts understood nationalist politics and gender through the stereotypes of English-educated babu, native politician, and the urban clerk. Imagetextual satire, for anticolonial and nationalist politics, framed these three stereotypes as both the oppressor and the oppressed in relationship to which other genders were conceived in colonial Bengal. These imagetextual stereotypes provided the bases for imagining the self and the other and a set of sensibilities, practices, and modes of sociability that defined late colonial South Asia. The circulation, co-existence, and deployment of these satirical discursive models for decolonial projects in English and vernacular illustrated periodicals stemmed from the nineteenth-century phenomenon of print erotophobia—the national and imperial fear of Indian erotic literature. I examine the imagetextual satire born in the wake of this print erotophobia at the intersections of class, gender, and nationalist politics. This cultural history of imagetexts also draws attention to the fictional properties of the colonial archival documents, which served as mediums of political exclusion and representation, history-recording, storytelling, and articulating nationalist sentiments.