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Considerations for LCA of Nanotechnologies

Jackie Isaacs

Center for High-rate Nanomanufacturing

Associate Director and ProfessorMechanical & Industrial EngineeringNortheastern University, Boston MA

Nanotechnology and Life Cycle Analysis WorkshopChicago, IL

November 5-6, 2009

EEC-0425826

CHN Vision: The Path from Nanoscience to Nanomanufacturing

Environment, Health and Safety

Regulation, Ethics and Education

Nanomanufacturing

CHN MissionTo bridge the gap between nanoscale scientific research and the

creation of nanotechnology-based commercial products

Nanoelements and templates

Assembly and Transfer Reliability

Manipulation of Trillions of Nanoelements

Metal 2

SWNTs

Parylene

Metal 1

Metal 2

SWNTs

Parylene

Metal 1

Applications inEnergyElectronicsBiomedicalMaterials

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Thrust 3: Applications

NEU; UML; UNH

Thrust 1:Nanoelements and

Nanotemplates NEU; UNH; UML

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Thrust 2:High-rate Assembly and

TransferNEU; UML; UNH

CHN Path to Nanomanufacturing

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What is High-rate Nanomanufacturing?CHN: Directed Assembly and Transfer

TechnologyPlatfom

Materials

Energy Electronics

Bio/Med

Structural

EMI-shielding

Flexible Electronics

Memory Devices

Biosensors

Photovoltaic

Batteries

Drug Delivery

CHN Applications Roadmap

Templates NanoelementsAssembly Processes

Transfer Processes

SubstratesPotential

Applications

Microwires template

Nanoparticles ElectrophoreticDirect transfer

(no functionalization)

Silicon

SWNT switch for nonvolatile

memory devices

Nanowires templates

Carbon nanotubes

(SWNTs and MWNTs)

Chemical Functionalization

Direct transfer with chemical

functionalizationPolymer

Polymer-based Biosensors

Nanotrench template

Conductive polymers

(PANi)

Electrophoretic and chemical

functionalization

No transfer needed

MetalNanoparticle-

based Biosensors

Template-free Polymer blends Dielectrophoretic 

 SWNT

Batteries

  Fullerenes       Photovoltaics

  Nanowires       EMI Shielding

CHN ToolboxConnects Research to Applications

CHN Toolbox: Process Flow for SWNT Switches

Templates Nanoelements Assembly Processes

Transfer Processes

Substrates Potential Applications

Microwires template

Nanoparticles ElectrophoreticDirect transfer

(no functionalization)

Silicon

SWNT switch for nonvolatile

memory devices

Nanowires templates

Carbon nanotubes (swnts and

mwnts)

Chemical functionalization

Direct transfer with chemical

functionalizationPolymer

Polymer-based biosensors

Nanotrench template

Conductive polymers (PANi)

Electrophoretic and chemical

functionalization

No transfer needed

MetalNanoparticle-

based biosensors

Template-free Polymer blends Dielectrophoretic 

  SWNT batteries

  Fullerenes       Photovoltaics

  Nanowires       EMI shielding

Thrust 3: Testbeds, Applications and Reliability

NEU; UML; UNH

Thrust 1: Nanoelements and

Nanotemplates NEU; UML; UNH

Thrust 2:High-rate

Assembly and TransferNEU; UML; UNH

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CHN Path to Nanomanufacturing

End-of-Life Impacts

High-rate Toxicity Screening

Environmental and Economic Uncertainties

Exposure Assessment& Control

Regulatory Issues

Social & Ethical Issues

9From Geraci, Jan 2008

Risk Management of Engineered Nanoparticles:

Fundamental Environmental Health/Safety Issues

1. Are exposures occurring ?

2. Are the exposures harmful ?

Answers lead to development of best practices to avoid harmful exposures

Project Leader: Ellenbecker, Tsai ,UML

Project Leaders: Rogers, Bello, UML

Worker Health & Safety Issues

• Airborne Exposure– Where do

nanoparticles reside?– Personal protective

equipment required?

• Dermal Exposure– Can particles

penetrate skin?– Gloves effective?– Personal protective

equipment required?

Respiratory System

Undertaken by Partner UML Toxics Use Reduction Institute

Different Air Flow and Vortex Patterns

Conventional hood Air-curtain hood

Compare Other Powder Handling Systems

• Biological safety cabinets scheduled for testing

• Development of best practices for powder handling

• Local enclosures (not conventional glove box) may provide improved protection for both workers and environment

0.0E+00

2.0E+03

4.0E+03

6.0E+03

8.0E+03

1.0E+04

1.2E+04

1.4E+04

10 100 1000Diameter, Dp[nm]

Num

ber c

once

ntra

tion

[ par

ticle

/cm

3]

vf= 1.0 m/s 190 ft/min, low sashvf= 0.6 m/s 114 ft/min,middle sashvf= 0.4 m/s 79 ft/min, high sashBZ 4 min after release stop,middle sash

Numerous Properties Impact ToxicityCharacterization of exposure hazards hampered by ability to measure multiple necessary physicochemical parameters implicated in the toxicity

Biological significance of measured properties and exposures is often unclear

• Surface Area

• Metals/Impurities

• Surface Charge

• Morphology

• Crystallinity

• Solubility in biological fluids

• Etc….

Nanomaterial Properties

Are these exposures

high, dangerous?

High Through-put Toxicity Screening Needed

• Thousands of functionalization variations for nanomaterials; existing toxicity testing approaches cannot handle in terms of complexity and cost

• A critical need exists for a simple, high-rate toxicity screening of nanomaterials….

Ferric Reducing Ability of Serum (FRAS) Method developed to address this need…

Project Leaders: Rogers, Bello, UML

Toxicology In Vitro2008

Inhalation Toxicology 2008

Measured Endpointsfrom Testing

Analysis of Predictive Utility of FRAS

19 NMs previouslyFRAS characterized

NMs characterized byCEIN and NIOSH

Additional NMsfrom vendors

4. Cellular Toxicity Testing(Eukaryotic Cells)

6. Acellular and CellularESR (NIOSH)

5. Gene Expression(Prokaryotic Cells)

• Intracellular oxidative stress• Extracellular oxidative stress• Mitochondrial damage• DNA damage• Apoptosis• Cell Viability

• Various stress genes• Genotoxicity biomarkers• DNA damage/repair • System genes activation

• Extracellular oxidative damage (includes multiple mechanisms)

• Extracellular reactive oxygen species

2. FRAS 3. Acellular DCFH

1. Physio-Chemical Characterization

NMs to Test

Characterization

and Testing

• Extracellular reactive oxygen species• Intracellular reactive oxygen species

• Statistical predictive models of endpoints• Develop a multi-tiered screening strategy• Compare FRAS with DCFH and ESR

Fun

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LCA Comparison of SWNT Mfg Processes

Journal of Industrial Ecology Special Nanotechnology Issue (Healy, Dahlben, Isaacs, 2008)

Focus on mfg phase of life cycle • Mass balance of processes to quantify products and emissions• Toxicological information of engineered nanomaterials not readily available• Impacts attributed to energy footprint

Fundamental Tradeoff Issues for Commercialization

May 19, 2008

Protecting Nanotech Workers from Health RisksBy Laura Walter http://www.occupationalhazards.com/

A study appearing in the May issue of Journal of Occupational and Environmental Medicine points out that nanotechnology companies must consider the steps they plan to take to protect the health of employees exposed to engineered nanoparticles.

“Companies currently involved with nanotechnology are faced withthe dilemma of balancing a desire to expand a potentially bountiful technology with limited knowledge about the potential hazards.”the dilemma of balancing a desire to expand a potentially bountiful

technology with limited knowledge about the potential hazards.”• Definitive toxicity results unavailable…• Uncertainty in risk of exposure…• How can companies responsibly

commercialize products?

Possible Risk Assessment Methods

for NanomaterialsMethod Pros & Cons

Monte Carlo models+ Allows modeling uncertainty- No tradeoff framework

Decision trees+ Allows insights with limited data- Can become overly complex

Bayesian belief networks+ Means for calculating conditional probabilities - No decision nodes

Influence diagrams+ Accounts for relationships- Compact representation

Multi-criteria decision making+ Tradeoff frontiers - Deterministic

Analytic hierarchy process+ Practically useful- Based on subjective opinions

Goal programming+ Can handle relatively large number of objectives- Deterministic

Desirability functions+ Can compare discrete alternatives, robust- Abstract approach, arbitrary weights

Life cycle assessment+ Systematic tool- Comparison of different studies is difficult

Given Current Uncertainty… Monte Carlo Simulation Model

Developed for SWNTsFour levels of EHS industrial hygiene defined :

None Low Level Medium Level High Level

Engineering Controls        

Ventilation    

Fume hoods    

Enclosure of processes      

Administrative Controls        

Annual worker training  

Air monitoring  

Medical monitoring  

Personal Protective Equipment        

Latex gloves      

Nitrile gloves    

Disposable    

HEPA filters      

Tyvek suits      

Respirators

Project Leaders: Benneyan, Isaacs NEU; Graduate Student: Ok

Gloves

Process-based Cost Model Conceptual Diagram

• Within TCMVariable Costs

Total Variable Cost

Raw material CostScrapped Material CostConsumable Materials CostDirect Labor CostEnergy CostIndirect Labor Cost

Fixed Costs

Total Fixed Cost

Main Equipment costAuxiliary Equipment CostOverhead Labor CostBuilding CostMaintenance CostInvestment

Other Costs

Costs external to model

General AdministrationMarketing and SalesShipping and ReceivingResearch and DevelopmentProfit and Taxes

Total Production Cost

SWNT HiPco Production Costs DeterminedBase case assumptions

– Production volume: 10,000 g/yr– Operating hours: 2000 hr/yr– Capital recovery rate: 10%– Overhead cost: 40% of direct labor– Maintenance cost: 5% equip. cost– Labor wage: $20/hr– Electricity cost: $0.10/kW*hr– Building cost: $13/ft2*yr

Ok, Benneyan, IsaacsJournal of Industrial Ecology

Special Nanotechnology Issue 2008

Monte Carlo Simulations

Method ObjectiveCHN Example Application

Potential Research Needs

Monte Carlo simulation

Comparison of alternate occupational health protection strategies

Monte Carlo risk models for HiPco nanomanufacturing process

Dose response curves could be included to model for better understanding of occupational health risks.

Multi-criteria decision making

Balancing reliability, exposure, and throughput for a nanomanufacturing process

Goal programming model for a nanomaterial production process

Nanoparticle monitoring results would inform the safety criteria in the analysis.

Desirability functions

Determining the most preferred product or process from various alternates

Desirability optimization for the selection of a specific product

Experimental design studies could help to have accurate process parameters.

Stochastic programming

Reliability and safety analysis for nanomanufacturing processes

Chance-constrained programming for a specific nanomanufacturing process

Involvement of researchers from different research areas would improve the theoretical modeling of the problem.

Creation of Risk Modeling Tools

Work underway on next case study related to fume hood work

Project Leaders: Benneyan, Isaacs; Graduate Student: Ok

Energy Use for SWNT Switch Mfg

Pre-diffusion Cleaning

10%

Oxidation7%

Pirahna Etch + Rinse Cleaning

7%

Photoresist Application0%

Bake0%

Electron Beam Lithography

71%

Photoresist Development4%

Inductively Coupled Plasma Etch

0%

Chrome Gold Deposition1% Photoresist Stripping

0%Carbon Nanotube

Deposition0%

Energy Use for CNT Switch Manufacture

Pre-diffusion Cleaning 

Oxidation 

Pirahna Etch + Rinse Cleaning 

Photoresist Application 

Bake 

Electron Beam Lithography 

Photoresist Development Inductively Coupled Plasma Etch 

Chrome Gold Deposition 

Photoresist Stripping 

Carbon Nanotube Deposition

Process Flow Diagram

CHN Overview 2008

SWNT Switch

Energy Use for SWNT Switch Mfg

Project Leader: Isaacs; Graduate Student: Dahlben

Environmental Assessment Using SimaPro

0.0E+00

1.0E-05

2.0E-05

3.0E-05

4.0E-05

5.0E-05

6.0E-05

7.0E-05

8.0E-05

9.0E-05

Carcinogens Airborne inorganics

Climate change Ecotoxicity Acidification/ Eutrophication

Land use Fossil fuels

Nor

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ized

impa

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Impact category

Pre-diffusion Cleaning

Oxidation

Pirahna Etch + Rinse Cleaning

Photoresist Application

Bake

EBL Switch

Photoresist Development

ICP Etch

Chrome Gold Deposition

Photoresist Stripping

Carbon Nanotube Deposition

HiPCO SWNT Process

CNT Switch Manufacture• Major impact categories:

– Airborne inorganics• Sulfuric acid used in

cleaning steps

– Climate change• CO2 release from

energy use

– Fossil fuels• Dominated by

energy-intensive equipment and operation time

Extend LCA Scope to Use and End-of-Life

Mfg.

Life Phase CNT switch Conventional

Use

EOL

TBD transistor

Environmental / economic comparison of SWNT switch to existing technology Estimation of energy during use phase Identification of potential barriers or advantages to recycling CNT materials

within existing infrastructure

From literature

TBD

Path Forward: Environmental & Economic Uncertainty

• Inherent tradeoffs and enormous uncertainty exist for nanomanufacturing costs and workplace exposure

• Until EHS research progresses, these modeling tools and analyses provide useful guidance for private & regulatory decisionmakers

• Multi-criteria modeling in future work will assess tradeoffs among economic, health, environmental, and societal impacts of nanoproducts

• Results from CHN exposure monitoring inform, enhance and complement this effort

• Systems approach for development of toolkit will support effective and responsible commercialization

Informed Decisions

Health &Eco-risks

Social Benefit

Engineered Nanomaterials

Nanotech Products

Nan

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• Range of social and ethical issues for emerging nanotechnologies• Social Context Issues

environmental justice, consumer safety/autonomy; privacy, unequal access

• Contested Moral Issues nano-enabled weapons, synthetic biology, embryonic stem cells

• Form of Life Issues conceptions of longevity and health, forms of sociability, artificial alternatives

• Technoculture Issues technofixes, commodification of nature, elitism in decision-making

• Transformational Issueshuman enhancement, artifactual persons

• Significance of issues to responsible development of nanotechnology

• Steps can be taken to begin addressing these issues

Nanotechnology: The Social and Ethical Issues

Project Leader: Ronald Sandler

Sandler, “Nanotechnology: The Social and Ethical Issues” Woodrow Wilson Center, Project on Emerging

Nanotechnologies, 2009 Available on-line

Integrated Systems Approach Required for Appropriate and Efficient Commercialization

Responsible Nanomanufacturing

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Social & Ethical Issues

Regulatory Issues

Enviro & Economic Uncertainties

EHS Assessment,

Tox Screening& EOL Impacts

Measure and control to determine best safety practices and screening methods for nanomaterials as well as impact of possible releases

Perform assessment of developing processes / products and evaluate tradeoffs for EHS (environmental health and safety) with costs

Promote informed policymaking

Advocate productive public discourse

with UML

with Benneyan

with Bosso NSF NIRT

with Sandler NSF NIRT

Acknowledgements

Funded by NSF Award Numbers SES-0404114 and EEC-0425826