Research projects

An Approach Based on Particle Swarm Optimization for Inspection of Spacecraft Hulls by a Swarm of Miniaturized Robots
Publication Venue: ANTS (2022) [To appear]
Advisor: Radhika Nagpal, Princeton University. Project Lead: Bahar Haghighat.

This project proposes the use of a swarm of miniaturized, vibration-sensing robots as a mobile sensor network. We utilize distributed inspection algorithms based on bio-inspired particle swarm optimization and evolutionary algorithm niching techniques to enumerate and localize a priori unknown vibration sources on the 2.5D hull of a spacecraft surface. We deploy the algorithms in simulation and on a fleet of cm-scale wheeled robots, finally demonstrating their operation in microgravity aboard a parabolic flight.

Mixels: Fabricating Interfaces using Programmable Magnetic Pixels
Publication Venue: UIST (2022)
Advisors: Stefanie Mueller, MIT and Ryo Suzuki, University of Calgary.

This project introduces a fabrication platform for programmable magnetic pixels that can be rapidly fabricated using an electromagnetic printhead. Our custom printhead clips onto a standard 3D printer and can both write and read magnetic pixel values from magnetic material. We provide a user interface that lets user specify the high-level magnetic behavior and that computes the underlying magnetic pixel assignments and fabrication instructions to program a magnetic surface.

Selective Self-Assembly using Re-Programmable Magnetic Pixels
Publication Venue: IROS (2022)
Advisors: Stefanie Mueller, MIT and Ryo Suzuki, University of Calgary.

This project introduces a method to generate highly selective encodings that can be magnetically "programmed" onto physical modules to enable them to self-assemble in chosen configurations. We generate these encodings based on Hadamard matrices, and show how to design the faces of modules to be maximally attractive to their intended mate, while remaining maximally agnostic to other faces. We derive guarantees on these bounds, and verify their attraction and agnosticism experimentally. Using cubic modules whose faces have been covered in soft magnetic material, we show how inexpensive, passive modules with planar faces can be used to selectively self-assemble into target shapes without geometric guides.

ElectroVoxel: Electromagnetically Actuated Pivoting for Scalable Modular Self-Reconfigurable Robots
Publication Venue: ICRA (2022) Press Videos:
Advisors: Stefanie Mueller, MIT and Ryo Suzuki, University of Calgary

ElectroVoxel is a cube-based reconfigurable robot that utilizes an electromagnet-based actuation framework to reconfigure in three dimensions via pivoting. Electromagnets embedded into the edges of each cube - or voxel - create repulsive or attractive forces to drive pivoting maneuvers or create hinges, respectively. We demonstrate self-reconfiguration on an air-table in the lab, and in microgravity on a parabolic flight.

LaserFactory: An Electromechanical Assembly and Fabrication Platform Integrated with a Laser Cutter to make Functional Devices and Robots
Publication Venue: CHI (2021) Press video:
Advisors: Steve Hodges, Microsoft Research Cambridge and Stefanie Mueller, MIT

LaserFactory is an integrated fabrication process that augments a commercially available fabrication machine to support the manufacture of fully functioning devices and robots without human intervention. In addition to creating 2D and 3D mechanical structures, LaserFactory creates conductive circuit traces with arbitrary geometries, picks-and-places electronic and electromechanical components, and solders them in place.

Curveboards: Integrating Breadboards into Physical Objects to Prototype Function in the Context of Form
Publication Venue: CHI (2020)
Advisor: Stefanie Mueller, MIT

CurveBoards are breadboards integrated into physical objects. In contrast to traditional breadboards, CurveBoards better preserve the object's look and feel while maintaining circuit fluidity, which enables designers to exchange and reposition components during design iteration. We provide an interactive editor that enables users to convert 3D models into CurveBoards and introduce a method to fabricate Curveboards using conductive silicone.

Fluifiber: Interweaving Moving Bodies over Distance via Programmable Tensegrity
Exhibition: Ars Electronica (2020)
Advisor: Hiroshi Ishii, MIT

Aspects of human movement that are unobserved visually, such as pressure and muscular tension, are represented by a programmable tensegrity structure that records and replays a dancer's body movements. We hypothesize that the nervous system, given abstract information in the form of a tangible dancing tensegrity structure, will endeavor to compensate for absent information in order to understand the body's movement in full.

Sequential Support: 3D Printing Dissolvable Support Material for Time-Dependent Mechanisms
Publication Venue: TEI (2019)
Advisor: Stefanie Mueller, MIT

We leverage the dissolution of standard support material (PVA) to enable applications beyond its traditional use case as a support structure for 3D prints. These include time-dependent mechanisms such as the timed release of scents from a 3D-printed structure sequentially overnight. To this end, we build a custom 3D editor plugin including a kinetic Monte Carlo simulation to create statistically accurate simulations for how the material dissolves over time.

An Electromagnetically Actuated, Self-Reconfigurable Space Structure
Publication Venue: ISTS (2017)
Advisor: Dario Izzo, European Space Agency

We present a conceptual framework for achieving on-orbit formation of reconfigurable space structures using individually actuated electromagnets embedded in the edges of large swarms of miniature spacecraft that are based on the PocketQube.

Feedback-Controlled Self-Folding of Autonomous Robot Collectives
Publication Venue: IROS (2016)
Advisor: Robert Wood, Harvard University

Design and fabrication of self-folding structures and robots. Starting with building composite materials from shape memory polymers, flexible PCBs and resistive heating elements, we implemented a controller to allow flat laminates to autonomously self-fold into arbitrary 3D configurations.

Visual Inertial Compassing
Research project (ETH Zurich, 2014).
Advisor: Roland Siegwart, ETH Zurich

Heading estimation using visual-inertial sensor fusion. Using low-cost IMUs and a stereo camera system, I developed algorithms to estimate a heading of North without a magnetometer by leveraging the rotation of the Earth using a Kalman Filter and a Full Batch Optimizer.

Modelling Bounding Gaits for a Quadrupedal Robot
Research project (in collaboration with Marius Fehr and Wilson Ko, ETH Zurich, 2013).
Advisor: Fumiya Iida, ETH Zurich (now Cambridge University)

In this project, the bounding gait of a quadrepdal robot was modelled, dividing each step into 3 phases; a lift-off phase, an aerial phase and a touch-down phase. The equations of motion are derived in 2 dimensions and solved in order to simulate several steps of the gait. Parallel to this, a 3d model of the bounding quadruped was simulated in a physics engine for comparison.