Interlocking metasuraces for modular microrobots

Modular micro robots have the potential to revolutionize several industries, ranging from targeted drug delivery to microassembly and search-and-rescue. Their key advantage lies in their reconfigurability: individual units can assemble into different configurations to perform various tasks, adapt to changing conditions, and maintain functionality through the replacement of failed modules.

While research in the field is quickly advancing, creating robust, non-permanent connectors between micro modules remains a challenge. Conventional solutions such as adhesives often provide permanent attachment and may require delicate surface preparation. Existing microscale connectors' geometries are constrained by fabrication limitations imposed by micromachining processes, restricting their functionality and implementation across robotic platforms.

This project aims to design, fabricate, and characterize microscale interlocking metasurfaces (ILMs) as an alternative attachment strategy. ILMs are architected arrays of mating surface features that enable non-permanent attachment between components. Unlike traditional joints, ILMs operate across a surface, providing robust mechanical attachment while allowing for repeated assembly and disassembly. Recent work has demonstrated their effectiveness at the macroscale for structural joining and vibration mitigation. Initial micro ILMs have been fabricated using high-resolution additive manufacturing (two-photon lithography), paving the way for their development and integration into microrobotic systems.

At the microscale, we hypothesize that small-scale forces (e.g., Van der Waals, electrostatic, and capillary forces) become significant and influence assembly and disassembly behaviors, as well as tensile strength. This project investigates how microscale forces affect, and can be leveraged to modulate, the performance of micro ILMs, focusing on electrostatic forces. We aim to answer the following question: how can electrostatic forces be leveraged to modulate the disassembly force?

To address this question, we will:

  1. Design micro-scale unit cells incorporating electrostatic actuation
  2. Fabricate selected designs using high-resolution additive manufacturing and microfabrication techniques
  3. Characterize the assembly and disassembly forces and tensile strength

Beyond tunable attachment, electrostatic micro ILMs may create multifunctional interfaces that combine structural joining with sensing: changes in capacitance may be used to monitor contact state or load history, enabling embedded health monitoring in micro-assemblies.

This project is conducted in collaboration with Professor Sarah Bergbreiter and the Center for Integrated Nanotechnologies (CINT) at Sandia National Laboratories. Depending on progress during the fall semester, there may be an opportunity to conduct experiments at CINT during January 2027 or Spring Break through an active user proposal.