Open Access
Content adaptation and depth perception in an affordable multi-view display
(MDPI, 2020) Ezcurdia Aguirre, Íñigo Fermín; Arregui Roldán, Adriana; Ardaiz Villanueva, Óscar; Ortiz, Amalia; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2019-000086; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1923
We present SliceView, a simple and inexpensive multi-view display made with multiple parallel translucent sheets that sit on top of a regular monitor; each sheet reflects different 2D images that are perceived cumulatively. A technical study is performed on the reflected and transmitted light for sheets of different thicknesses. A user study compares SliceView with a commercial light-field display (LookingGlass) regarding the perception of information at multiple depths. More importantly, we present automatic adaptations of existing content to SliceView: 2D layered graphics such as retro-games or painting tools, movies and subtitles, and regular 3D scenes with multiple clipping z-planes. We show that it is possible to create an inexpensive multi-view display and automatically adapt content for it; moreover, the depth perception on some tasks is superior to the one obtained in a commercial light-field display. We hope that this work stimulates more research and applications with multi-view displays.
Open Access
Holographic acoustic elements for manipulating levitating particles. Applications in human-computer interaction
(2016) Marzo Pérez, Asier; Ardaiz Villanueva, Óscar; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
En esta tesis doctoral demostramos simultáneamente atrapamiento 3D, traslación y rotación de las partículas utilizando dispositivos de una sola cara. Esto se logra mediante el ajuste de manera óptima los retardos de fase usados para alimentar los transductores; de esta manera se generan estructuras acústicas sin precedentes y sin recurrir a lentes físicas, transductores hechos a medida o accionamiento mecánico. Nuestro método genera trampas óptimas en las posiciones deseadas con cualquier disposición espacial de los transductores; además, mejora significativamente los manipuladores anteriores. Presentamos tres trampas acústicas óptimas: trampas pinza, un nuevo fenómeno acústico que también puede rotar objetos; trampas tornado, cuyas capacidades de levitación se mostraron teóricamente y recientemente se observaron experimentalmente usando una lente acústica fija; y trampas en botella, que nunca han sido ni probadas ni sugeridas para levitar objetos. También introducimos el concepto de elementos holográficos acústicos basado en la interpretación de los retardos de fase como una placa holográfica que combina la codificación de elementos acústicos. Esta teoría permite el análisis y la generación eficiente de trampas acústicas, así como comparaciones con trampas ópticas. Este trabajo lleva las ventajas de la levitación óptica (es decir, un solo haz, rotación, control holográfico y múltiples partículas) a la eficiencia y versatilidad de la levitación acústica. Como resultado, esperamos el desarrollo de potentes rayos tractores, pantallas físicas 3D o control de micro-máquinas que están dentro de nuestro cuerpo. Nuevas aplicaciones en interacción hombre-máquina (IHM) se pueden derivar de la posibilidad de posicionar en medio del aire objetos a distancia e incluso a través de obstáculos. En la configuración más básica, movemos partículas sobre una superficie para pintar sobre la arena o líquidos a distancia y sin contacto. Un sistema más avanzado puede posicionar un par de objetos en 3D, esto nos permite representar funciones y posiciones de objetos tales como aviones o asteroides. El objetivo final sería crear un display compuesto de cientos de partículas que levitan de forma independiente para formar diferentes formas.
Open Access
PointerVol: a laser pointer for swept volumetric displays
(ACM, 2024-10-11) Fernández Ortega, Unai Javier; Sarasate Azcona, Iosune; Ezcurdia Aguirre, Íñigo Fermín; López-Amo Ocón, Manuel; Fernandez Fernandez, Ivan; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
A laser pointer is a commonly used device that does not require communication with the display system or modifications on the applications, the presenter can just take a pointer and start using it. When a laser pointer is used on a volumetric display, a line rather than a point appears, making it not suitable for pointing at 3D locations. PointerVol is a modified laser pointer that allows users to point to 3D positions inside a swept volumetric display. We propose two PointerVol implementations based on timing and distance measurements, we evaluate the pointing performance using them. Finally, we present other features such as multi-user pointing, line patterns and a multi-finger wearable. PointerVol is a simple device that can help to popularize volumetric displays, or at least to make them more usable for presentations with true-3D content.
Open Access
Contactless electrostatic piloerection for haptic sensations
(IEEE, 2023) Iriarte Cárdenas, Naroa; Ezcurdia Aguirre, Íñigo Fermín; Elizondo Martínez, Sonia; Irisarri Erviti, Josu; Hemmerling, Daria; Ortiz Nicolás, Amalia; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
In this project, we create artificial piloerection using contactless electrostatics to induce tactile sensations in a contactless way. Firstly, we design various high-voltage generators and evaluate them in terms of their static charge, safety and frequency response with different electrodes as well as grounding strategies. Secondly, a psychophysics user study revealed which parts of the upper body are more sensitive to electrostatic piloerection and what adjectives are associated with them. Finally, we combine an electrostatic generator to produce artificial piloerection on the nape with a head-mounted display, this device provides an augmented virtual experience related to fear. We hope that work encourages designers to explore contactless piloerection for enhancing experiences such as music, short movies, video games, or exhibitions.
Open Access
Holographic acoustic elements for manipulation of levitated objects
(Nature Publishing Group, 2015) Marzo Pérez, Asier; Seah, Sue Ann; Drinkwater, Bruce W.; Sahoo, Deepak Ranjan; Long, Benjamin; Subramanian, Sriram; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
Sound can levitate objects of different sizes and materials through air, water and tissue. This allows us to manipulate cells, liquids, compounds or living things without touching or contaminating them. However, acoustic levitation has required the targets to be enclosed with acoustic elements or had limited manoeuvrability. Here we optimize the phases used to drive an ultrasonic phased array and show that acoustic levitation can be employed to translate, rotate and manipulate particles using even a single-sided emitter. Furthermore, we introduce the holographic acoustic elements framework that permits the rapid generation of traps and provides a bridge between optical and acoustical trapping. Acoustic structures shaped as tweezers, twisters or bottles emerge as the optimum mechanisms for tractor beams or containerless transportation. Single-beam levitation could manipulate particles inside our body for applications in targeted drug delivery or acoustically controlled micro-machines that do not interfere with magnetic resonance imaging.
Open Access
Numerical and experimental investigation of the stability of a drop in a single-axis acoustic levitator
(American Institute of Physics, 2019) Brizzotti Andrade, Marco Aurélio; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
Acoustic levitation can be employed to hold liquid drops in midair, enabling novel applications in X-ray scattering of proteins, amorphous crystallization of solutions, or contactless mixing. Multiple studies have characterized the physical behavior of a levitated drop inside an acoustic field. Here, we present a numerical and experimental study on the acoustic levitation of water drops in a single-Axis acoustic levitator consisting of an ultrasonic transducer and an opposing reflector. Instead of modeling an abstract incident acoustic field, our model considers the shape of the drop as well as the real geometry of the levitator. We also use a high-speed camera to observe the disintegration and the undesired oscillations of the drops. Our results show that the insertion of a drop in the levitator provokes a shift in its resonant frequency that depends on the shape of the drop. Second, the levitation behavior depends on whether the levitator operates slightly below or above the resonance. Third, if the levitator is driven above the resonant frequency, it is possible to levitate with more strength and avoid disintegration of the drop. This research provides an insight on how to achieve more stable experiments that avoid the bursting and undesired oscillations of the levitated sample. We hope that it will facilitate numerous experiments involving acoustically levitated liquid drops.
Open Access
LeviPrint: contactless additive manufacturing using acoustic levitation with position and orientation control of elongated parts
(2021) Ezcurdia Aguirre, Íñigo Fermín; Morales González, Rafael; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
LeviPrint assembles small objects in a contactless way using ultrasonic phased-arrays and optimization algorithms. We explore a set of methods that enables 6 Degrees-of-Freedom (DoF) control of elongated bodies. We then evaluate different ultrasonic arrangements to optimize the manipulation of these bodies. The combination of arrangements and optimization algorithms allow us to levitate, orientate and assemble complex objects. These techniques and arrangements can be leveraged for the microfabrication of electromechanical components and in-vivo additive manufacturing. We highlight the reduction of cross-contamination and the capability to manufacture inside closed containers from the outside.
Open Access
Hand-as-a-prop: using the hand as a haptic proxy for manipulation in virtual reality
(Springer, 2023) Marichalar Baraibar, Sebastian Roberto; Ezcurdia Aguirre, Íñigo Fermín; Morales González, Rafael; Ortiz Nicolás, Amalia; Marzo Pérez, Asier; Ardaiz Villanueva, Óscar; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Haptic feedback can be almost as important as visual information in virtual reality environments. On the one hand, in Active Haptic Feedback, specialized devices such as vibrotactile gloves are employed; however, these solutions can be expensive, vendor-specific or cumbersome to setup. On the other hand, Passive Haptic Feedback approaches use inexpensive objects as proxies for the virtual entities; but mapping virtual objects to real props is not scalable nor flexible. We propose the Hand-as-a-Prop technique, which consists in using human hands as object props. We implemented two modalities: Self, where the user¿s non-dominant hand act as the virtual object while the dominant hand grabs, translates and releases it; and External, where the hand of another person is used. Hand-as-a-Prop can represent multiple shapes with a single prop and does not require extra hardware. We performed an evaluation comparing both Self and External Hand-as-a-Prop with traditional Object Props in terms of user experience (goodness, ease, realism, fatigue, and preference) and performance (task completion time and translation time). Results showed that Hand-as-a-Prop was rated as neutral tending to positive, and in some cases, the performance was similar to Object Props. Users preferred Self Hand-as-a-Prop over External Hand-as-a-Prop and also obtained better results.
Open Access
Contactless pick-and-place of millimetric objects using inverted near-field acoustic levitation
(American Institute of Physics, 2020) Brizzotti Andrade, Marco Aurélio; Ramos, Tiago S.; Adamowski, Julio C.; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
We model and realize an ultrasonic contactless pick-and-place device capable of picking, self-centering, self-orienting, translating, and releasing flat millimetric objects. The device is an ultrasonic Langevin transducer operating at 21 kHz that radiates into air through a tapered tip. Objects are trapped few micrometers below the tip due to the near-field acoustic levitation phenomenon. We first investigate the conditions to achieve an attractive force on the object depending on its size and the device operating frequency. Second, we use a 3D acoustic model that describes the converging forces and torque that provide the self-centering and self-orienting capabilities. Third, a more advanced Computational Fluid Dynamics model based on the Navier-Stokes equations explains the small gap between the tip and the trapped object. The contactless manipulation capabilities of the device are demonstrated by picking, transporting, and releasing a Surface Mount Device in air. The presented manipulation concept can be an interesting alternative for manipulating delicate objects such as microelectromechanical devices, silicon dies, or micro-optical devices.
Open Access
An interdisciplinary design of an interactive cultural heritage visit for in-situ, mixed reality and affective experiences
(MDPI, 2022) Olaz Moratinos, Xabier; García Marreros, Ricardo M.; Ortiz Nicolás, Amalia; Marichalar Baraibar, Sebastian Roberto; Villadangos Alonso, Jesús; Ardaiz Villanueva, Óscar; Marzo Pérez, Asier; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
Interactive technologies, such as mixed-reality and natural interactions with avatars, can enhance cultural heritage and the experience of visiting a museum. In this paper, we present the design rationale of an interactive experience for a cultural heritage place in the church of Roncesvalles at the beginning of Camino de Santiago. We followed a participatory design with a multidisciplinary team which resulted in the design of a spatial augmented reality system that employs 3D projection mapping and a conversational agent acting as the storyteller. Multiple features were identified as desirable for an interactive experience: interdisciplinary design team; in-situ; mixed reality; interactive digital storytelling; avatar; tangible objects; gestures; emotions and groups. The findings from a workshop are presented for guiding other interactive cultural heritage experiences. © 2022 by the authors.