arXiv subjects

Sinan Haliyo

Publications and source records attributed to Sinan Haliyo.

7 recordsLinked to original sources

arXiv2026

Gear-based 3D-printed Micromachines Actuated by Optical Tweezers

The miniaturization of mechanical mechanisms is crucial to enable the development of compact, high-performance micromachines. However, the downscaling actuation of conventional gears and micromotors has remained limited by the inherent challenges of implementing mechanical/electrical powering. Here, we present the design, fabrication, and characterization of an optomechanical, gear-driven micromachine realized through two-photon polymerization 3D printing. The actuation is achieved using optical tweezers. The device integrates a microgear transmission system with an optically actuated part, enabling light-controlled micromachines. When illuminated by a highly focused laser source, the first gear generates rotational torque within the gear assembly, converting optical energy into directional mechanical work that can be transmitted to the coupled gear. We demonstrate the fabrication of micromachines using two-photon polymerization (2PP) laser writing, enabling the fabrication of spur gear trains and bevel gears that can produce out-of-plane rotations, which is not achievable with traditional micromachining fabrication techniques. The micromachines are composed of a single gear or a train of two or three gears without any unwanted adhesion between the components, leading to functioning systems. Experimentally, the fabricated micromachines were actuated using optical tweezers, demonstrating continuous gear rotation, effective motion transmission in gear trains, out-of-plane rotations, and the ability to amplify velocity or torque. Optical-tweezer actuation broadens the potential applications of these micromachines, particularly in biomedical and lab-on-a-chip systems, where precise, minimally invasive control at the microscale is essential.

physics.optics↗

arXiv2026

Soft 3D Metamaterial for Low-Frequency Elastic Waves

Acoustic metamaterials offer exceptional control over wave propagation, but their potential remains unfulfilled due to fabrication constraints. Conventional processes yield mostly rigid, planar structures, whereas soft-matter alternatives have so far been confined to ultrasounds. This work overcomes prior limitations with a fully soft 3D metamaterial operating around 200Hz. The design combines a 3D-printed elastomer lattice with resonant inclusions of liquid metal, injected via a network of mesofluidic channels. Its dynamic response is derived from a hybrid strategy uniting a lumped-element model with finite element analysis. Simulations reveal how the dual-phase design decouples flexural and torsional modes, opening a subwavelength band gap for low-frequency elastic waves. Empirical validation is achieved via a custom camera-based vibrometer. Its high spatiotemporal resolution and full-field capabilities enable direct capture of local modes and evanescent waves underlying the band gap. Accelerometer data corroborate these findings and demonstrate greater attenuation than common silicone elastomers at only half of the density. By combining scalable fabrication, compliance, and operations at frequencies relevant to human tactile perception, this novel metamaterial paves the way for lightweight, high-performance cushioning and handles that protect users from harmful vibration exposure.

cond-mat.soft↗

arXiv2024

Dynamic Shaping of Multi-Touch Stimuli by Programmable Acoustic Metamaterial

Acoustic metamaterials are artificial structures, often lattice of resonators, with unusual properties. They can be engineered to stop wave propagation in specific frequency bands. Once manufactured, their dispersive qualities remain invariant in time and space, limiting their practical use. Actively tuned arrangements have received growing interest to address this issue. Here, we introduce a new class of active metamaterial made from dual-state unit cells, either vibration sources when powered or passive resonators when left disconnected. They possess self-tuning capabilities, enabling deep subwavelength band gaps to automatically match the carrier signal of powered cells, typically around 200Hz. Swift electronic commutations between both states establish the basis for real-time reconfiguration of waveguides and shaping of vibration patterns. A series of experiments highlight how these tailored acceleration fields can spatially encode information relevant to human touch. This novel metamaterial can readily be made using off-the-shelf smartphone vibration motors, paving the way for a widespread adoption of multi-touch tactile displays.

physics.app-ph↗

arXiv2024

Optical chiral microrobot for out-of-plane rotation

Optical microrobots (OPTOBOTs) have garnered significant interest, particularly in the medical field, due to their potential for precise cell manipulation in various biological studies and microsurgical applications. Previously described OPTOBOTs demonstrate multiple degrees of freedom, yet improvements are needed, especially in achieving reliable out-of-plane rotation. Here, we propose an OPTOBOT design based on chirality that enables full-cycle out-of-plane rotations using optical tweezers. The OPTOBOT has an arrow-like structure with two handles aligned on the same axis, maintaining its horizontal orientation and facilitating controlled movement. Additionally, the OPTOBOT's tail is a chiral helix, which induces repetitive out-of-plane rotations around its longer axis when targeted by a laser beam that is due to broken axial parity. Finite element analysis is employed to design the OPTOBOT and assess its capacity to generate mono-directional high optical torque. Experimental results confirm various actuation modes, supporting future integration of OPTOBOTs in complex micromanipulation tasks.

physics.optics↗

arXiv2023

Optimized Sandwich and Topological Structures for Enhanced Haptic Transparency

Humans rely on multimodal perception to form representations of the world. This implies that environmental stimuli must remain consistent and predictable throughout their journey to our sensory organs. When it comes to vision, electromagnetic waves are minimally affected when passing through air or glass treated for chromatic aberrations. Similar conclusions can be drawn for hearing and acoustic waves. However, tools that propagate elastic waves to our cutaneous afferents tend to color tactual perception due to parasitic mechanical attributes such as resonances and inertia. These issues are often overlooked, despite their critical importance for haptic devices that aim to faithfully render or record tactile interactions. Here, we investigate how to optimize this mechanical transmission with sandwich structures made from rigid, lightweight carbon fiber sheets arranged around a 3D-printed lattice core. Through a comprehensive parametric evaluation, we demonstrate how this design paradigm provides superior haptic transparency, regardless of the lattice types. Drawing an analogy with topology optimization, our solution approaches a foreseeable technological limit. It offers a practical way to create high-fidelity haptic interfaces, opening new avenues for research on tool-mediated interactions.

cond-mat.mtrl-sci↗

arXiv2021

"Can I Touch This?": Survey of Virtual Reality Interactions via Haptic Solutions

Haptic feedback has become crucial to enhance the user experiences in Virtual Reality (VR). This justifies the sudden burst of novel haptic solutions proposed these past years in the HCI community. This article is a survey of Virtual Reality interactions, relying on haptic devices. We propose two dimensions to describe and compare the current haptic solutions: their degree of physicality, as well as their degree of actuation. We depict a compromise between the user and the designer, highlighting how the range of required or proposed stimulation in VR is opposed to the haptic interfaces flexibility and their deployment in real-life use-cases. This paper (1) outlines the variety of haptic solutions and provides a novel perspective for analysing their associated interactions, (2) highlights the limits of the current evaluation criteria regarding these interactions, and finally (3) reflects the interaction, operation and conception potentials of "encountered-type of haptic devices".

cs.HC↗

arXiv2020

CoVR: A Large-Scale Force-Feedback Robotic Interface for Non-Deterministic Scenarios in VR

We present CoVR, a novel robotic interface providing strong kinesthetic feedback (100 N) in a room-scale VR arena. It consists of a physical column mounted on a 2D Cartesian ceiling robot (XY displacements) with the capacity of (1) resisting to body-scaled users' actions such as pushing or leaning; (2) acting on the users by pulling or transporting them as well as (3) carrying multiple potentially heavy objects (up to 80kg) that users can freely manipulate or make interact with each other. We describe its implementation and define a trajectory generation algorithm based on a novel user intention model to support non-deterministic scenarios, where the users are free to interact with any virtual object of interest with no regards to the scenarios' progress. A technical evaluation and a user study demonstrate the feasibility and usability of CoVR, as well as the relevance of whole-body interactions involving strong forces, such as being pulled through or transported.

cs.HC↗