@article{12822,
  abstract     = {Gears and cogwheels are elemental components of machines. They restrain degrees of freedom and channel power into a specified motion. Building and powering small-scale cogwheels are key steps toward feasible micro and nanomachinery. Assembly, energy injection, and control are, however, a challenge at the microscale. In contrast with passive gears, whose function is to transmit torques from one to another, interlocking and untethered active gears have the potential to unveil dynamics and functions untapped by externally driven mechanisms. Here, it is shown the assembly and control of a family of self-spinning cogwheels with varying teeth numbers and study the interlocking of multiple cogwheels. The teeth are formed by colloidal microswimmers that power the structure. The cogwheels are autonomous and active, showing persistent rotation. Leveraging the angular momentum of optical vortices, we control the direction of rotation of the cogwheels. The pairs of interlocking and active cogwheels that roll over each other in a random walk and have curvature-dependent mobility are studied. This behavior is leveraged to self-position parts and program microbots, demonstrating the ability to pick up, direct, and release a load. The work constitutes a step toward autonomous machinery with external control as well as (re)programmable microbots and matter.},
  author       = {Martinet, Quentin and Aubret, Antoine and Palacci, Jérémie A},
  issn         = {2640-4567},
  journal      = {Advanced Intelligent Systems},
  number       = {1},
  publisher    = {Wiley},
  title        = {{Rotation control, interlocking, and self‐positioning of active cogwheels}},
  doi          = {10.1002/aisy.202200129},
  volume       = {5},
  year         = {2023},
}

@article{10280,
  abstract     = {Machines enabled the Industrial Revolution and are central to modern technological progress: A machine’s parts transmit forces, motion, and energy to one another in a predetermined manner. Today’s engineering frontier, building artificial micromachines that emulate the biological machinery of living organisms, requires faithful assembly and energy consumption at the microscale. Here, we demonstrate the programmable assembly of active particles into autonomous metamachines using optical templates. Metamachines, or machines made of machines, are stable, mobile and autonomous architectures, whose dynamics stems from the geometry. We use the interplay between anisotropic force generation of the active colloids with the control of their orientation by local geometry. This allows autonomous reprogramming of active particles of the metamachines to achieve multiple functions. It permits the modular assembly of metamachines by fusion, reconfiguration of metamachines and, we anticipate, a shift in focus of self-assembly towards active matter and reprogrammable materials.},
  author       = {Aubret, Antoine and Martinet, Quentin and Palacci, Jérémie A},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  number       = {1},
  publisher    = {Springer Nature},
  title        = {{Metamachines of pluripotent colloids}},
  doi          = {10.1038/s41467-021-26699-6},
  volume       = {12},
  year         = {2021},
}