# Universal Mechanical Polycomputation in Granular Matter

arXiv: https://arxiv.org/abs/2305.17872 · HTML: https://mlsanity.com/paper/2305.17872/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- Builds on 4 of its 25 references that are in the map.
- First posted on arXiv 29 May 2023.

## Builds on (most cited first, 4 of 4)

- [The Hardware Lottery](https://mlsanity.com/paper/2009.06489/) (2020)
- [Physical reservoir computing -- An introductory perspective](https://mlsanity.com/paper/2005.00992/) (2020)
- [There's Plenty of Room Right Here: Biological Systems as Evolved, Overloaded, Multi-scale Machines](https://mlsanity.com/paper/2212.10675/) (2022)
- [Evolving Programmable Computational Metamaterials](https://mlsanity.com/paper/2204.08651/) (2022)

## Built on by (most cited first, 2 of 2)

- [Gradient-based Design of Computational Granular Crystals](https://mlsanity.com/paper/2404.04825/) (2024)
- [Data-driven Modeling of Granular Chains with Modern Koopman Theory](https://mlsanity.com/paper/2411.15142/) (2024)

## Abstract (arXiv)

Unconventional computing devices are increasingly of interest as they can operate in environments hostile to silicon-based electronics, or compute in ways that traditional electronics cannot. Mechanical computers, wherein information processing is a material property emerging from the interaction of components with the environment, are one such class of devices. This information processing can be manifested in various physical substrates, one of which is granular matter. In a granular assembly, vibration can be treated as the information-bearing mode. This can be exploited to realize "polycomputing": materials can be evolved such that a single grain within them can report the result of multiple logical operations simultaneously at different frequencies, without recourse to quantum effects. Here, we demonstrate the evolution of a material in which one grain acts simultaneously as two different NAND gates at two different frequencies. NAND gates are of interest as any logical operations can be built from them. Moreover, they are nonlinear thus demonstrating a step toward general-purpose, computationally dense mechanical computers. Polycomputation was found to be distributed across each evolved material, suggesting the material's robustness. With recent advances in material sciences, hardware realization of these materials may eventually provide devices that challenge the computational density of traditional computers.