Indices for Environmental Sustainability in Pneumatic Soft Robotic Actuators: A Systematic Review

Soft robots are increasingly advancing into heterogeneous contexts, however they still suffer from different sustainability issues including limited lifetime, disposal and poor energy efficiency. These issues severely limit their spread usage thus leading to the need for new materials and efficient actuation systems. The main goal of this work is to find out in scientific literature the main indicators concerning environmental sustainability in pneumatically actuated soft robots. To reach this goal, we used the PRISMA methodology to explore, in a systematic manner, available indices related to environmental dimension of sustainability. The indicators found are reported with the absolute and relative metrics adapted from the references and two proposed categorizations: i) one related to the part of soft robotic system, ii) the other one related to the LCA-oriented Product Lifecycle (PL) phase. The study highlights the lack in the literature of indicators related to energy consumption regarding environmental dimension of the manufacturing process, thus opening the possibility of future studies in this direction.