# Active Materials: Biological Benchmarks and Transport Limitations

## TL;DR

This paper reviews biological active materials, focusing on metabolic activity and transport limitations that influence size and functionality in living organisms and biomimetic systems.

## Contribution

It provides a comprehensive survey of metabolic processes and transport constraints in active matter, highlighting size limitations relevant to biomimetic applications.

## Key findings

- Transport of fuel, waste, and heat limits the size of active systems.
- Metabolic activity varies widely across organisms and influences active material design.
- Transport constraints are critical in understanding the capabilities of biological and synthetic active materials.

## Abstract

These lecture notes were prepared for the 2018 Summer School on `Active Matter and Non-equilibrium Statistical Physics' at l'\'{E}cole de Physique des Houches. They survey metabolic activity across a wide range of living organisms, and consider size limitations due to the transport of fuel, waste, and heat for active materials at biomimetic levels of activity.