@phdthesis{20276,
  abstract     = {Complex 3D shapes can be created by morphing flat 2D configurations. Such deformations
either preserve the intrinsic material geometry (e.g., folding paper) or modify it through
localized contraction. Once transformed, the 3D shape can be further controlled to achieve a
target functionality. A key challenge is to take the material specifications and the actuation
process as input to automatically design the target 3D shape and its functionality. This thesis
presents two novel computational pipelines for the design and control of shape-morphing
structures used to create functional prototypes.
The first pipeline borrows from the art of origami to fold paper into intricate shapes and
applies this principle to make 3D lighting displays. We introduce, PCBend a computational
design approach that covers a surface with individually addressable RGB LEDs, effectively
forming a low-resolution surface by folding rigid printed circuit boards (PCBs). We optimize
cut patterns on PCBs to act as hinges and co-design LED placement, circuit routing, and
fabrication constraints to produce PCB blueprints. The PCBs are fabricated using automated
standard manufacturing services with LEDs embedded on them. Finally, the fabricated PCBs
are cut along the contour and folded onto a 3D-printed support. The 3D lighting display is
then controlled to display complex surface light patterns.
Creating 3D shapes through folding is only possible if their planar configuration, called ”unfolding” exists without any distortion or overlap. Existing methods often permit distortion
or require multiple patches, which are unsuitable for fabrication pipelines that rely on folding
non-stretchable materials. We reinforce such fabrication pipelines by providing a geometric
relaxation to the problem, where the input shape is modified to admit overlap-free unfolding.
The second fabrication pipeline extends shape morphing to soft robotics by emulating nature’s
blueprint of distributed actuation. Inspired by vertebrates, we build musculoskeletal robots
using modular active actuators, employing Liquid Crystal Elastomers (LCEs) as shrinkable
artificial muscles integrated with 3D-printed bones. The chemical composition of LCEs is
altered to enable untethered actuation through infrared radiation, allowing active control of
individual muscles and their corresponding bones. The combined motion of individual bones
defines the robot’s overall shape and functionality. Our proposed system significantly expands
both the design and control spaces of soft robots, which we harness using our computational
design tools. We build several physical robots that exhibit complex shape morphing and varied
terrain navigation, showcasing the versatility of our pipeline.
This thesis explores applications ranging from intricate light patterns displayed on 3D shapes
formed by folding rigid PCBs to untethered robots that use contractile muscles to exhibit
shape morphing and locomotion. Through these examples, the thesis highlights how computational design and distributed actuation, integrated with novel materials, can transform
passive structures into functional prototypes.},
  author       = {Bhargava, Manas},
  isbn         = {978-3-99078-065-7},
  issn         = {2663-337X},
  pages        = {96},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Design and control of deformable structures: From PCB lighting displays to elastomer robots}},
  doi          = {10.15479/AT-ISTA-20276},
  year         = {2025},
}

@article{18565,
  abstract     = {We present a computational approach for unfolding 3D shapes isometrically into the plane as a single patch without overlapping triangles. This is a hard, sometimes impossible, problem, which existing methods are forced to soften by allowing for map distortions or multiple patches. Instead, we propose a geometric relaxation of the problem: We modify the input shape until it admits an overlap‐free unfolding. We achieve this by locally displacing vertices and collapsing edges, guided by the unfolding process. We validate our algorithm quantitatively and qualitatively on a large dataset of complex shapes and show its proficiency by fabricating real shapes from paper.},
  author       = {Bhargava, Manas and Schreck, Camille and Freire, M. and Hugron, P. A. and Lefebvre, S. and Sellán, S. and Bickel, Bernd},
  issn         = {1467-8659},
  journal      = {Computer Graphics Forum},
  keywords     = {fabrication, single patch unfolding, mesh simplification},
  number       = {1},
  publisher    = {Wiley},
  title        = {{Mesh simplification for unfolding}},
  doi          = {10.1111/cgf.15269},
  volume       = {44},
  year         = {2025},
}

@unpublished{20286,
  abstract     = {Natural organisms utilize distributed actuation through their musculoskeletal
systems to adapt their gait for traversing diverse terrains or to morph their
bodies for varied tasks. A longstanding challenge in robotics is to emulate
this capability of natural organisms, which has motivated the development of
numerous soft robotic systems. However, such systems are generally optimized
for a single functionality, lack the ability to change form or function on
demand, or remain tethered to bulky control systems. To address these
limitations, we present a framework for designing and controlling robots that
utilize distributed actuation. We propose a novel building block that
integrates 3D-printed bones with liquid crystal elastomer (LCE) muscles as
lightweight actuators, enabling the modular assembly of musculoskeletal robots.
We developed LCE rods that contract in response to infrared radiation, thereby
providing localized, untethered control over the distributed skeletal network
and producing global deformations of the robot. To fully capitalize on the
extensive design space, we introduce two computational tools: one for
optimizing the robot's skeletal graph to achieve multiple target deformations,
and another for co-optimizing skeletal designs and control gaits to realize
desired locomotion. We validate our framework by constructing several robots
that demonstrate complex shape morphing, diverse control schemes, and
environmental adaptability. Our system integrates advances in modular material
building, untethered and distributed control, and computational design to
introduce a new generation of robots that brings us closer to the capabilities
of living organisms.},
  author       = {Bhargava, Manas and Hiraki, Takefumi and Strugaru, Irina-Malina and Zhang, Yuhan and Piovarci, Michael and Daraio, Chiara and Iwai, Daisuke and Bickel, Bernd},
  booktitle    = {arXiv},
  title        = {{Computational design and fabrication of modular robots with untethered control}},
  doi          = {10.48550/arXiv.2508.05410},
  year         = {2025},
}

@article{13049,
  abstract     = {We propose a computational design approach for covering a surface with individually addressable RGB LEDs, effectively forming a low-resolution surface screen. To achieve a low-cost and scalable approach, we propose creating designs from flat PCB panels bent in-place along the surface of a 3D printed core. Working with standard rigid PCBs enables the use of
established PCB manufacturing services, allowing the fabrication of designs with several hundred LEDs. 
Our approach optimizes the PCB geometry for folding, and then jointly optimizes the LED packing, circuit and routing, solving a challenging layout problem under strict manufacturing requirements. Unlike paper, PCBs cannot bend beyond a certain point without breaking. Therefore, we introduce parametric cut patterns acting as hinges, designed to allow bending while remaining compact. To tackle the joint optimization of placement, circuit and routing, we propose a specialized algorithm that splits the global problem into one sub-problem per triangle, which is then individually solved.
Our technique generates PCB blueprints in a completely automated way. After being fabricated by a PCB manufacturing service, the boards are bent and glued by the user onto the 3D printed support. We demonstrate our technique on a range of physical models and virtual examples, creating intricate surface light patterns from hundreds of LEDs.},
  author       = {Freire, Marco and Bhargava, Manas and Schreck, Camille and Hugron, Pierre-Alexandre and Bickel, Bernd and Lefebvre, Sylvain},
  issn         = {1557-7368},
  journal      = {Transactions on Graphics},
  keywords     = {PCB design and layout, Mesh geometry models},
  location     = {Los Angeles, CA, United States},
  number       = {4},
  publisher    = {Association for Computing Machinery},
  title        = {{PCBend: Light up your 3D shapes with foldable circuit boards}},
  doi          = {10.1145/3592411},
  volume       = {42},
  year         = {2023},
}