Lowering Embodied Energy through Digital Fabrication & nanoscale-design

Lowering Embodied Energy through Digital Fabrication & nanoscale-design Ankur Podder | podder@mit.edu Design Fabrication Group, IDC, MIT (P.I.: Prof. Lawrence Sass | Design & Computation)

Abstract (click to read further) • Can you point at any non-biological entity or artefact around you (including ‘smart’ products) and extract information on its embodied energy?

• As the world progresses in controlling its carbon footprint by lowering operating energy to near-zero, embodied energy (emergy) of artefacts becomes crucial to be understood, controlled and lowered further.

• Conventional manufacturing, construction and waste-management processes are decentralised, top=down and do not have boundaryless emergy=information flow through life-cycle of the artefact. This make it difficult to inquire into emergy involved during the design stage, production stage and the end-of-life stage.

• Use of digital design like CAD and digital fabrication tools like additive & subtractive manufacturing (AM&SM) can lead to centralized and closed-environment manufacturing. Digital fabrication tools further inform design of artefacts such that it could be disassembled and re-used, thereby conserving the emergy.

• To retrieve information regarding embodied energy of an artefact at any stage of its life-cycle, its structural, electronic, mechanical and informational parts are to be designed and fabricated using digital tools at nanometer scales.

• The abstract proposes a boundaryless emergy-information flow across digitally fabricated product’s life-cycle.

Material & Methods

PRE-LIFE

(click to read further)

1. AM & SM: Emergy involved in additive and subtractive manufacturing (3D printing & CNC milling).

2. CAD environment for nanoscale designs: The digital design and fabrication process initiates in the CAD environment. This is to script plugins into 3D modelling space that guides and informs a designing process for lowering embodied energy.

Results

(click to read further) HOW CAN WE EXTRACT AND STORE THE EMERGY HERE?

BEGIN-LIFE HOW CAN WE EXTRACT AND STORE THE EMERGY HERE?

END-LIFE

• Documentation of all inter-stage emergyinformation across the artefact’s lifecycle.

• Nanoscale-design and digital fabrication of large artefacts that are finest tangible examples of emergy-aware nonbiological entity.

1-Artefact in CAD environment designed through nanoscale-design approach

2-Guiding and informing sustainable design And fabrication in CAD and CAM environment.

3- 3D-printed using PLA and emergyinformation documented in the process of product development

4- Subtractive manufacturing using flat stock and emergyinformation documnetation during process.

Abstract Figure 1. Towards Boundaryless Emergy-Information Flow

• Figure 1 presents the three stages during the life-cycle of artefacts • Information regarding Embodied energy can be considered to be part of ‘black box’, that is non-quantifiable in applied situations, no current solutions of on-body storage of such information as well as no scope of retrieval or extraction when needed • Boundaryless emergy-information flow would lead to more informed design and use decisions in subsequent stages of the life-cycle of a product • Point-to=point updating of emergy-information would lead to better disassembly and reuse practices during end-of-life • Visualizing emergy-information and practices to lower it at early stage of design and fabrication would lead to cascading effects on driving down operating energy during use-stage, thus avoiding mechanical systems that lead to ‘zero-energy’ solutions during occupancy or usage.

Emergy & Digital Fabrication • The initial emergy in artefacts (of any scale) represents the non-renewable energy consumed in the acquisition of raw materials, their processing, manufacturing/ construction and transportation. In short, the energy required in production of the artefact. The initial emergy has two components: ‘Direct energy’ used to transport materials and then to ‘make’ the artefact; and ‘Indirect energy’ used to acquire, process, and manufacture the materials, including any transportation related to these activities. [1] The ‘recurring emergy’ represents the nonrenewable energy consumed to maintain, repair, restore, refurbish or replace materials, components or systems during the life-cycle of the artefact. [2] • Emergy is measured as the quantity of non-renewable energy per unit of production material, component or system. It is expressed in megajoules (MJ) or gigajoules (GJ) per unit weight (kg or tonne) or area (m^2) • Carbon-based nanoparticles, i.e., carbon nano-fibers, carbon nano-tubes and fullerenes require 1-900 giga joule per kilogram (GJ/kg) of primary energy to produce, compared with ~200 mega joule per kilogram (MJ/kg) for aluminum. This is mainly attributed to the fact that nanomaterials involve an energy intensive synthesis process, or additional mechanical process to reduce particle size. [3] Thus, alternative fabrication techniques at nanoscale that includes top=dpwn and bottom-up nano fabrication is essential to bring sustainability to use of digital fabrication tools [4], especially for bottom-up nanoscale designing of larger artefacts. [5] • For experimentation, 3D-printing using alternatives like biomaterials is initially tested. [6]

References: 1. Duque Ciceri, N., Gutowski, T. G., & Garetti, M. (2010). A tool to estimate materials and manufacturing energy for a product. Institute of Electrical and Electronics Engineers.

2. Crowther, P. (1999). Design for disassembly to recover embodied energy.

3. Kim, H. C., & Fthenakis, V. (2013). Life cycle energy and climate change implications of nanotechnologies.

Journal of Industrial Ecology, 17(4), 528-541.

4. Faludi, J., Hu, Z., Alrashed, S., Braunholz, C., Kaul, S., & Kassaye, L. (2015, February). Does material choice drive sustainability of 3D printing?. In International Conference on Mechanical Engineering and Manufacturing (Vol. 17).

5. Zhang, X., Sun, C., & Fang, N. (2004). Manufacturing at nanoscale: Top-down, bottom-up and system engineering. Journal of Nanoparticle Research, 6(1), 125-130.

6. Van Wijk, A. J. M., & van Wijk, I. (2015). 3D printing with biomaterials: Towards a sustainable and circular economy. IOS press.

Materials and Methods • For experimentation, PLA (Polylactic Acid) is considered. Latest 3D-printing fabrication tools employ these in great extent. The experiment follows a product design and development process where the embodied energy involved in each step is documented.

• Moving beyond conventional approach of life-cycle analysis that initiates from Begin-Of-Life, ‘pre-life’ emergy on materials like PLA that is used majorly in 3D-printing fabrication tools is considered.

• Methodology: Product Design and development along with artefact’s life-cycle analysis.

• At every stage of the ‘making’ process, the emergy involved is calculated using simulation tools and documented.

PRE-LIFE

PRE-L In MJ/kg Or In MJ/m^2

+ In MJ/kg Or In MJ/m^2

EOL

HOW CAN WE EXTRACT AND STORE THE EMERGY HERE?

BEGIN-OF-LIFE HOW CAN WE EXTRACT AND STORE THE EMERGY HERE?

BOL

END-OF-LIFE

Results

• Documentation of all inter-stage emergy-information across the artefact’s life-cycle.

• Nanoscale-design and digital fabrication of large artefacts that are finest tangible examples of emergy-aware non-biological entity.

• Devising best-practices for emergy-aware design in CAD environment.