Shadi Khazaaleh

Springs inspired by the Kresling origami pattern have recently gained prominence as a foundation for developing functional engineering systems with versatile properties, catering to niche applications across various technological fields. With minimal adjustments to their geometric parameters, the restoring force of such springs can be tuned to exhibit quasi-zero stiffness (QZS) behavior that is ideal for designing low-frequency vibration isolators. In this work, we present the design, fabrication, and performance analysis of a fully functional, ultra-low-frequency torsional vibration isolator based on the Kresling origami spring. Fabricated from single-phase Nylon PA12 using selective laser sintering, the isolator weighs less than 5 grams and combines high static stiffness with low dynamic stiffness, enabling compact, scalable, and cost-effective isolation solutions. Unlike many existing QZS designs that are complex or suited only for large systems, this design is easily manufactured, durable, and well-suited for precision engineering. Quasi-static torsional tests reveal a broad QZS region, while dynamic testing shows a nearly linear response and effective vibration attenuation beginning at frequencies as low as 2.5 Hz, even under large-amplitude excitations. Furthermore, the isolator shows high endurance to prolonged cyclic loading with negligible performance degradation. These findings highlight the potential of origami-inspired structures in creating scalable, high-performance vibration isolators and provide a strong foundation for future research in advanced dynamic applications.

We present the design and evaluation of a simple, compact and efficient electromagnetic energy harvesting tile that can be used to harness energy from footsteps. The proposed harvester incorporates a translational–rotational origami-inspired coupling mechanism to transform the axial loads exerted by human footsteps into a localized rotation of an electromagnetic generator. The coupling mechanism employs a non-rigid tunable Kresling spring, the restorative behaviour of which is tunable to maximize energy transduction from the applied load to the generator. A computational model is developed to optimize the design parameters of the mechanism, which are then utilized to fabricate a prototype of the energy harvester. The tile is tested under loading conditions that mimic a human step, where it is demonstrated that it is capable of generating 4.18 W of electrical power per step with a surface power density of 2609 μW cm ⁻² . This article is part of the theme issue ‘Origami/Kirigami-inspired structures: from fundamentals to applications’.

The design of effective and compact energy absorption systems is key to the survivability and durability of many man-made structures and machines. To this end, this work presents the design, assessment, and implementation of a novel origami-inspired energy absorber that is based on the Kresling origami pattern. The absorber consists of a Kresling origami column positioned between the loading point and an energy dissipation module. By exploiting its unique inherent translation-to-rotation coupling feature, the primary function of the Kresling column is to transmit uniaxial incident loads (shock or impact) into localized rotational energy that can then be dissipated in a viscous fluid chamber. The proposed system has several unique advantages over traditional designs including the ability to (i) dissipate energy associated with both torsional and uniaxial loads, (ii) control the rotational velocity profile to maximize energy dissipation, and (iii) customize the restoring-force behavior of the Kresling column to different applications. Furthermore, the proposed design is more compact since it can realize the same stroke distance of the traditional translational design while being considerably shorter. Through extensive computational modeling, parametric studies, and experimental testing, it is demonstrated that the proposed design can be optimized to absorb all the imparted energy; and out of the absorbed energy, around 40% can be dissipated in the viscous fluid, while the rest is either dissipated by the viscoelasticity of the origami column or stored in it as potential energy.

Structures inspired by the Kresling origami pattern have recently emerged as a foundation for building functional engineering systems with versatile characteristics that target niche applications spanning different technological fields. Their light weight, deployability, modularity, and customizability are a few of the key characteristics that continue to drive their implementation in robotics, aerospace structures, metamaterial and sensor design, switching, actuation, energy harvesting and absorption, and wireless communications, among many other examples. This work aims to perform a systematic review of the literature to assess the potential of the Kresling origami springs as a structural component for engineering design keeping three objectives in mind: (i) facilitating future research by summarizing and categorizing the current literature, (ii) identifying the current shortcomings and voids, and (iii) proposing directions for future research to fill those voids.

Origami, the art of paper folding, addresses traditionally conflicting requirements for designing both powerful and low-cost haptic interfaces. As of today, there are no comprehensive reviews that cover origami-inspired haptic actuation, sensing, design processes, and fabrication. To fill this void, this paper summarizes existing origami-inspired haptic technologies in terms of workspace, degrees of freedom (DoF), power consumption, control methods, sensing, and actuation. The paper also presents an iterative design process for pattern generation and origami-inspired haptic characterization. Using this design process, we demonstrate a case study that involves the design, development, and evaluation of a novel syringe haptic interface for dental simulation. Our main findings suggest that origami-inspired haptics need more mathematically optimized and versatile design, as well as novel materials that offer a room for embedded sensing and actuation.

Although medical simulators have benefited from the use of haptics and virtual reality (VR) for decades, the former has become the bottleneck in producing a low-cost, compact, and accurate training experience. This is particularly the case for the inferior alveolar nerve block (IANB) procedure in dentistry, which is one of the most difficult motor skills to acquire. As existing works are still oversimplified or overcomplicated for practical deployment, we introduce an origami-based haptic syringe interface for IANB local anesthesia training. By harnessing the versatile mechanical tunability of the Kresling origami pattern, our interface simulated the tactile experience of the plunger while injecting the anesthetic solution. We present the design, development, and characterization process, as well as a preliminary usability study. The force profile generated by the syringe interface is perceptually similar with that of the Carpule syringe. The usability study suggests that the haptic syringe significantly improves the IANB training simulation and its potential to be utilized in several other medical training/simulation applications.

Current architectured cellular cushion materials rely mainly on damage and/or unpredictable collapse of their unit cells to absorb and dissipate energy under impact. This prevents shape recovery and produces undesirable force fluctuations that limit reusability and reduce energy absorption efficiency. Here, we propose to combine advanced manufacturing technologies with Origami principles to create a new class of architectured cellular viscoelastic cushion material which combines low weight and high energy absorption efficiency with damage resistance and full behavior customization. Each unit cell in the proposed material is inspired by the Kresling Origami topology, which absorbs impact energy by gracefully folding the different interfaces forming the cell to create axial and rotational motions. A large part of the absorbed energy is then dissipated through viscoelasticity and friction between the interfaces. The result is a nearly ideal cushion material exhibiting high energy absorbing efficiency (around 70%) combined with high energy dissipation (94% of the absorbed energy). The material is also tunable for optimal performance, reliable despite successive impact events, and achieves full shape recovery.