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Joshua Pearce is a cross-appointed Professor at the Ivey and the Department of Electrical & Computer Engineering. He is the John M. Thompson Chair in Information Technology and Innovation at the Thompson Centre for Engineering Leadership & Innovation. His research spans areas of solar photovoltaic technology, open hardware, distributed recycling and additive manufacturing, policy and economics.
Joshua runs the Free Appropriate Sustainability Technology (FAST) research group. He has worked with, consulted for, and been funded by dozens of renewable energy and additive manufacturing companies as well as the US Government and the UN.
His research was the first to show that levelized cost of solar photovoltaic electricity was economically competitive in North America, the first to demonstrate that open hardware can save scientists 90-99% on research costs, and the first to show that household level distributed recycling and manufacturing were technically feasible, less environmentally harmful and profitable for consumers. His research is regularly covered by the international and national press and it is continually ranked in the top 0.1% on Academia.edu. He is the editor-in-chief of HardwareX, the first journal dedicated to open source scientific hardware and the author of the Open-Source Lab:How to Build Your Own Hardware and Reduce Research Costs, Create, Share, and Save Money Using Open-Source Projects, and To Catch the Sun, an open source book on how to harness solar energy.
Joshua Pearce received his Ph.D. in Materials Engineering from the Pennsylvania State University. He then developed the first Sustainability program in the Pennsylvania State System of Higher Education and helped develop the Collaborative Applied Sustainability graduate engineering program while at Queen's University, Canada. Then he was the first Richard Witte Professor of Materials Science and Engineering and a Professor cross-appointed in the Department of Electrical & Computer Engineering at the Michigan Technological University where he inaugurated and was the faculty advisor for the Michigan Tech Open Source Hardware Enterprise and ran the Open Sustainability Technology Research Group. He was a Fulbright-Aalto University Distinguished Chair and a visiting professor of Photovoltaics and Nanoengineering at Aalto University as well as a visiting Professor Équipe de Recherche sur les Processus Innovatifs (ERPI), Université de Lorraine, France.
Dr. Pearce is always looking for motivated research students and collaborators. See here.
Abstract: The high volume of plastic waste and the extremely low recycling rate have created a serious challenge worldwide. Local distributed recycling and additive manufacturing (DRAM) offers a solution by economically incentivizing local recycling. One DRAM technology capable of processing large quantities of plastic waste is fused granular fabrication, where solid shredded plastic waste can be reused directly as 3D printing feedstock. This study presents an experimental assessment of multi-material recycling printability using two of the most common thermoplastics in the beverage industry, polyethylene terephthalate (PET) and high-density polyethylene (HDPE), and the feasibility of mixing PET and HDPE to be used as a feedstock material for large-scale 3-D printing. After the material collection, shredding, and cleaning, the characterization and optimization of parameters for 3D printing were performed. Results showed the feasibility of printing a large object from rPET/rHDPE flakes, reducing production costs by up to 88%.
Abstract: The application of computer vision and machine learning methods for semantic segmentation of the structural elements of 3D-printed products in the field of additive manufacturing (AM) can improve real-time failure analysis systems and potentially reduce the number of defects by providing additional tools for in situ corrections. This work demonstrates the possibilities of using physics-based rendering for labeled image dataset generation, as well as image-to-image style transfer capabilities to improve the accuracy of real image segmentation for AM systems. Multi-class semantic segmentation experiments were carried out based on the U-Net model and the cycle generative adversarial network. The test results demonstrated the capacity of this method to detect such structural elements of 3D-printed parts as a top (last printed) layer, infill, shell, and support. A basis for further segmentation system enhancement by utilizing image-to-image style transfer and domain adaptation technologies was also considered. The results indicate that using style transfer as a precursor to domain adaptation can improve real 3D printing image segmentation in situations where a model trained on synthetic data is the only tool available. The mean intersection over union (mIoU) scores for synthetic test datasets included 94.90% for the entire 3D-printed part, 73.33% for the top layer, 78.93% for the infill, 55.31% for the shell, and 69.45% for supports.
Abstract: Open-source design of medical devices, following the concept of frugal engineering, provides unrestricted descriptions of technical details, allowing the low-cost and local fabrication of devices to reduce global inequities in healthcare.
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Open AccessReview
A Review of 3D Printing Batteries
by Maryam Mottaghi 1 andJoshua M. Pearce 2,*ORCID
1
Department of Mechanical and Materials Engineering, Western University, London, ON N6A 3K7, Canada
2
Department of Electrical and Computer Engineering, Ivey Business School, Western University, London, ON N6A 3K7, Canada
*
Author to whom correspondence should be addressed.
Batteries 2024, 10(3), 110; https://doi.org/10.3390/batteries10030110
Submission received: 13 February 2024 / Revised: 12 March 2024 / Accepted: 13 March 2024 / Published: 18 March 2024
(This article belongs to the Section Battery Processing, Manufacturing and Recycling)
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Abstract
To stabilize the Earth’s climate, large-scale transition is needed to non-carbon-emitting renewable energy technologies like wind and solar energy. Although these renewable energy sources are now lower-cost than fossil fuels, their inherent intermittency makes them unable to supply a constant load without storage. To address these challenges, rechargeable electric batteries are currently the most promising option; however, their high capital costs limit current deployment velocities. To both reduce the cost as well as improve performance, 3D printing technology has emerged as a promising solution. This literature review provides state-of-the-art enhancements of battery properties with 3D printing, including efficiency, mechanical stability, energy and power density, customizability and sizing, production process efficiency, material conservation, and environmental sustainability as well as the progress in solid-state batteries. The principles, advantages, limitations, and recent advancements associated with the most common types of 3D printing are reviewed focusing on their contributions to the battery field. 3D printing battery components as well as full batteries offer design flexibility, geometric freedom, and material flexibility, reduce pack weight, minimize material waste, increase the range of applications, and have the potential to reduce costs. As 3D printing technologies become more accessible, the prospect of cost-effective production for customized batteries is extremely promising.
Abstract: Purpose
Both the capital cost and levelized cost of electricity of utility-scale ground-mounted solar photovoltaic (PV) systems are less than those of representative residential-scale solar rooftop systems. There is no life cycle analysis (LCA) study comparing the environmental impact of rooftop PV system and large utility-scale solar PV system. This study aims to fill this knowledge gap and provide a comprehensive LCA of a representative 7.4 kWp rooftop and 3.5 MWp utility-scale solar PV systems from cradle to grave.
Methods
The energy as well as CO2 and water footprint during the manufacture, use, and end of life of both systems will be quantified. The primary focus of this study will be on the LCA of racking/mounting systems as these are the greatest source of divergence between the two main system types. In addition, sensitivities are run on (1) PV module types, (2) footings for the ground-mounted systems, and (3) geographic locations in different states of the USA.
Results
Overall, the embodied energy per kWp of the rooftop-mounted PV system is 21–54% lower than that of the utility-scale ground-mounted PV system. The higher embodied energy of the ground-mounted systems is so much larger than the rooftop systems that even sub-optimally oriented rooftops still have substantially lower energy payback times in all regions. Similarly, the greenhouse gas emissions attributed to the ground-mount system with rack a is 2.5 times, and ground-mount system with rack b is 1.2 times greater per kWp than that of the rooftop system. A rooftop solar PV system requires 21 to 54% less input energy, emits 18 to 59% less CO2eq. of greenhouse gas emissions, and consumes a reduced quantity of water ranging from 1 to 12% per kWp. The energy payback time of rooftop solar systems is approximately 51 to 57% lower than that of ground-mounted solar systems across all locations.
Conclusions
Overall the CO2 payback time was 378 to 428% higher for ground-mounted PV compared to rooftop PV for the same modules and 125 to 142% higher for ground-mounted compared to rooftop PV for the most common modules used for both applications. Although water use is dominated by the PV modules themselves, it is important to note that the water consumption for the utility-scale ground rack is approximately 260 times (rack a) and 6 times (rack b) higher than that of the rooftop mounting structure.
Abstract: Alternative food sources are essential in both low-resource settings and during emergencies like abrupt sunlight reduction scenarios. Seaweed presents a promising option but requires investigation into the viability of unconventionally sourced ropes for harvesting. In this regard, a low-cost reliable method to test the tensile strength of rope is needed to validate alternative materials for use in harvesting seaweed. Commercial rope testing jigs alone range in price from several thousand to tens of thousands of dollars, so there is interest in developing a lower-cost alternative. Addressing these needs, this article reports on an open-source design for tensile strength rope testing hardware. The hardware design focuses on using readily available parts that can be both sourced from a hardware store and manufactured with simple tools to provide the greatest geographic accessibility. The jig design, which can be fabricated for CAD 20, is two to three orders of magnitude less expensive than commercially available solutions. The jig was built and tested using a case study example investigating denim materials (of 1 5/8”, 3 1/4”, 4 7/8”, 6 1/2”, and 8 1/8” widths) as a potential alternative rope material for seaweed farming. Denim demonstrated strengths of up to 1.65 kN for the widest sample, and the jig demonstrated sufficient strength and stiffness for operations at forces below 4 kN. The results are discussed and areas for future improvements are outlined to adapt the device to other circumstances and increase the strength of materials that can be tested.
Abstract: Although solar photovoltaic (PV) system costs have declined, capital cost remains a barrier to widespread adoption. Do-it-yourself (DIY) system designs can significantly reduce labor costs, but if they are not attached to a building structure, they require ground penetrating footings. This is not technically and economically feasible at all sites. To overcome these challenges, this study details systems designed to (1) eliminate drilling holes and pouring concrete, (2) propose solutions for both fixed and variable tilt systems, (3) remain cost effective, and (4) allow for modifications to best fit the user’s needs. The ballast-supported foundations are analyzed for eight systems by proposing two separate ballast designs: one for a single line of post systems, and one for a double line of post systems, both built on a 4-kW basis. The results of the analysis found that both designs are slightly more expensive than typical in-ground concrete systems by 25% (assuming rocks are purchased at a landscaping company), but the overall DIY system’s costs remain economically advantageous. Sensitivity analyses are conducted to show how modifications to the dimensions influence the weight of the system and thus change the economic value of the design, so users can trade dimensional freedom for cost savings, and vice versa. Overall, all wood-based PV racking system designs provide users with cost-effective and easy DIY alternatives to conventional metal racking, and the novel ballast systems presented provide more versatility for PV systems installations.
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Open AccessArticle
Towards Sustainable Protein Sources: The Thermal and Rheological Properties of Alternative Proteins
by Kaitlyn Burghardt 1,Tierney Craven 1,Nabil A. Sardar 2 andJoshua M. Pearce 3,*ORCID
1
Department of Chemical & Biochemical Engineering, Western University, London, ON N6A 5B9, Canada
2
BeeHex, LLC, Columbus, OH 43230, USA
3
Department of Electrical & Computer Engineering and Ivey Business School, Western University, London, ON N6A 5B9, Canada
*
Author to whom correspondence should be addressed.
Foods 2024, 13(3), 448; https://doi.org/10.3390/foods13030448
Submission received: 4 January 2024 / Revised: 26 January 2024 / Accepted: 29 January 2024 / Published: 31 January 2024
(This article belongs to the Special Issue Agro-Food Chain By-Products and Plant Origin Food to Obtain High-Value-Added Foods)
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Abstract
Reducing meat consumption reduces carbon emissions and other environmental harms. Unfortunately, commercial plant-based meat substitutes have not seen widespread adoption. In order to enable more flexible processing methods, this paper analyzes the characteristics of commercially available spirulina, soy, pea, and brown rice protein isolates to provide data for nonmeat protein processing that can lead to cost reductions. The thermal and rheological properties, as well as viscosity, density, and particle size distribution, were analyzed for further study into alternative protein-based food processing. The differential scanning calorimetry analysis produced dry amorphous-shaped curves and paste curves with a more distinct endothermic peak. The extracted linear temperature ranges for processing within food production were 70–90 °C for spirulina, 87–116 °C for soy protein, 67–77 °C for pea protein, and 87–97 °C for brown rice protein. The viscosity analysis determined that each protein material was shear-thinning and that viscosity increased with decreased water concentration, with rice being an exception to the latter trend. The obtained viscosity range for spirulina was 15,100–78,000 cP, 3200–80,000 cP for soy protein, 1400–32,700 cP for pea protein, and 600–3500 cP for brown rice protein. The results indicate that extrusion is a viable method for the further processing of protein isolates, as this technique has a large temperature operating range and variable screw speed. The data provided here can be used to make single or multi-component protein substitutes.
Abstract: The prohibitive costs of small-scale solar photovoltaic (PV) racks decrease PV adoption velocity. To overcome these costs challenges, an open hardware design method is used to develop two novel variable tilt racking designs. These are the first stilt-mounted racking designs that allow for the manual change of the tilt angle from zero to 90 degrees by varying the length of cables. The racks are designed using the calculated dead, wind, and snow loads for Canada as a conservative design for most of the rest of the world. Structural capacities of the wooden members are then ascertained and the resisting bending moment, shear force, tensile force, and compressive force is calculated for them. A structural and truss analysis is performed to ensure that the racking design withstands the applicable forces. Moreover, the implications of changing the tilt angle on the wooden members/cables used to build the system are also determined. The systems offer significant economic savings ranging from one third to two thirds of the capital expenses of the commercially available alternatives. In addition, the racking designs are easy-to-build and require minimal manufacturing operations, which increases their accessibility. The stilt-mounted designs can be employed for agrivoltaic settings while allowing farm workers shaded, ergonomic access to perform planting, weeding, and harvesting.
Abstract: As additive manufacturing rapidly expands the number of materials including waste plastics and composites, there is an urgent need to reduce the experimental time needed to identify optimized printing parameters for novel materials. Computational intelligence (CI) in general and particle swarm optimization (PSO) algorithms in particular have been shown to accelerate finding optimal printing parameters. Unfortunately, the implementation of CI has been prohibitively complex for noncomputer scientists. To overcome these limitations, this article develops, tests, and validates PSO Experimenter, an easy-to-use open-source platform based around the PSO algorithm and applies it to optimizing recycled materials. Specifically, PSO Experimenter is used to find optimal printing parameters for a relatively unexplored potential distributed recycling and additive manufacturing (DRAM) material that is widely available: low-density polyethylene (LDPE). LDPE has been used to make filament, but in this study for the first time it was used in the open source fused particle fabrication/fused granular fabrication system. PSO Experimenter successfully identified functional printing parameters for this challenging-to-print waste plastic. The results indicate that PSO Experimenter can provide 97% reduction in research time for 3D printing parameter optimization. It is concluded that the PSO Experimenter is a user-friendly and effective free software for finding ideal parameters for the burgeoning challenge of DRAM as well as a wide range of other fields and processes.
Abstract: Purpose
This study aims to apply an open-source approach to protect the 3D printing industry from innovation stagnation due to broad patenting of obvious materials.
Design/methodology/approach
To do this, first an open-source implementation of the first five conditions of an open-source algorithm developed to identify all obvious 3-D printing materials was implemented in Python, and the compound combinations of two and three constituents were tested on ten natural and synthetic compounds. The time complexity for combinations composed of two constituents and three constituents is determined to be O(n2) and O(n3), respectively.
Findings
Generating all combinations of materials available on the Chemical Abstracts Services (CAS) registry on the fastest processor on the market will require at least 73.9 h for the latter, but as the number of constituents increases the time needed becomes prohibitive (e.g. 3 constituents is 1.65 million years). To demonstrate how machine learning (ML) could help prioritize both theoretical as well as experimental efforts a three-part biomaterial consisting of water, agar and glycerin was used as a case study. A decision tree model is trained with the experimental data and is used to fill in missing physical properties, including Young's modulus and yield strength, with 84.9 and 85.1% accuracy, respectively.
Originality/value
The results are promising for an open-source system that can theoretically generate all possible combinations of materials for 3-D printing that can then be used to identify suitable printing material for specific business cases based on desired material properties.
Abstract: Proprietary bottle rolling systems automate some laboratory applications, however, their exorbitant costs limit accessibility. This study provides designs of an open source bottle roller that is compatible with distributed digital manufacturing using 3-D printed parts and readily-available commercial components. The experimental results show that the open source bottle roller can be fabricated for CAD$210 (about USD$150) in materials, which is 86% less expensive than the most affordable proprietary bottle roller on the market. The design, however, is more robust with enhanced capabilities. The design can be adapted to the user’s needs, but is already ccompatible with incubators with a low profile (dimensions 50x46x8.8cm) and capable of being operated at elevated temperatures. The systems can be adjusted to revolves from 1 to 200 RPM, exceeding the rotational speed of most commercial systems. The open source bottle roller as tested has a capacity greater than 6 kg and can roll 12 100mL bottles simultaneously. Validation testing showed that it can operate for days at 80 RPM without human intervention or monitoring for days at both room temperature and elevated temperatures (50oC). Future work includes adapting the designs for different sizes and for different fabrication techniques to further reduce costs and increase flexibility.
Abstract: Tourniquets are effective for casualty-prevention in emergency situations. The use of centrally-manufactured commercial tourniquets, however, is not always possible due to supply chain disruptions. The open-source hardware model has been applied to overcome these disruptions in humanitarian crises and several low-cost digitally manufacturable open-source tourniquets have been developed. With the low reliability of improvised tourniquets, it is important to ensure that distributed manufacturing of tourniquets is effective and safe. Tourniquets can be tested, but existing tourniquet testers are expensive, bulky, and complex to operate, which limits their accessibility to an even greater extent than tourniquets in extreme settings. This article fulfills a need by providing a small, transportable, open-source additive-manufactured tourniquet tester that enables inexpensive and accurate testing of tourniquets against known clinical parameters. The <$100 tourniquet tester is validated and tested for operating force of tourniquets in the field or in distributed manufacturing facilities. The tourniquet tester has a significant economic and operational advantage compared to proprietary counterparts available on the market. Once calibrated with a blood pressure monitor, the built-in LCD displays the measuring range of the tester as 0 to 200 N, which is enough to test the validation of all tourniquets.
Abstract: When attempting to quantify future harms caused by carbon emissions and to set appropriate energy policies, it has been argued that the most important metric is the number of human deaths caused by climate change. Several studies have attempted to overcome the uncertainties associated with such forecasting. In this article, approaches to estimating future human death tolls from climate change relevant at any scale or location are compared and synthesized, and implications for energy policy are considered. Several studies are consistent with the “1000-ton rule,” according to which a future person is killed every time 1000 tons of fossil carbon are burned (order-of-magnitude estimate). If warming reaches or exceeds 2 °C this century, mainly richer humans will be responsible for killing roughly 1 billion mainly poorer humans through anthropogenic global warming, which is comparable with involuntary or negligent manslaughter. On this basis, relatively aggressive energy policies are summarized that would enable immediate and substantive decreases in carbon emissions. The limitations to such calculations are outlined and future work is recommended to accelerate the decarbonization of the global economy while minimizing the number of sacrificed human lives.
