Is laser-induced graphene (LIG) environmentally sustainable? Laboratory-scale life cycle assessment of LIG from petroleum- and bio-derived precursors

Purpose: This study explores the application of Life Cycle Assessment (LCA) to the production of laser-induced graphene (LIG), a graphene-based material obtained through direct laser ablation of carbon-rich precursors. LIG has been hailed as a sustainable alternative to conventional graphene production technologies due to the potential use of renewable feedstocks; however, no LCA has yet assessed its actual environmental performance. This study presents the first LCA of lab-scale LIG production from one petroleum-derived polymer (polyimide) and two bio-derived sources, based on maize starch and waste almond shell powder, respectively. It identifies process hotspots, focusing on energy demand and precursor contributions, and also highlights methodological challenges in early-stage LCA of emerging technologies. Methods: LIG production process from the three precursors was modeled according to a cradle-to-gate approach, using primary experimental data from laboratory measurements, to construct the Life Cycle Inventory. The functional unit is set as the production of 1 cm2 of LIG on its precursor, meaning that LIG is not removed from the precursor after the scribing process. Environmental impacts were assessed using the Environmental Footprint 3.1 method, including all 16 impact categories, with contribution analysis for each precursor–LIG pair. The Cumulative Energy Demand (CED) was also calculated and compared to other graphene production routes. Lastly, sensitivity analysis was performed, exploring two renewable energy scenarios to assess potential improvements. Results and discussion: Results show that laser energy use is the primary environmental impact driver for LIG production, outweighing the influence of precursor type. As a result, the potential benefits of using bio-derived precursors are not yet captured, as they currently only influence the selection of optimal laser writing parameters. Also, LIG resulted comparable to other graphene production methods in terms of energy demand. At the current technological maturity, the transition toward energy-efficient solutions represents the key step for optimizing the environmental sustainability of the LIG production process. Conclusion: Laser scribing, often proposed as a sustainable approach for graphene synthesis, currently suffers from high energy intensity that offsets the benefits of using renewable precursors. However, results may vary if system boundaries are extended to a cradle-to-grave analysis, eventually considering process scale-up scenarios and including data on the human and environmental toxicity of graphene-based materials. While these aspects cannot yet be integrated into the LCA of LIG production, this study represents a first step toward a clearer understanding of its environmental impact, hopefully contributing to advancing its technological readiness level.