Open Access
Microfluidic platform using focused ultrasound passing through hydrophobic meshes with jump availability
(Oxford University Press, 2023) Koroyasu, Yusuke; Nguyen, Thanh-Vinh; Sasaguri, Shun; Marzo Pérez, Asier; Ezcurdia Aguirre, Íñigo Fermín; Nagata, Yuuya; Yamamoto, Tatsuya; Nomura, Nobuhiko; Hoshi, Takayuki; Ochiai, Yoichi; Fushimi, Tatsuki; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
Applications in chemistry, biology, medicine, and engineering require the large-scale manipulation of a wide range of chemicals, samples, and specimens. To achieve maximum efficiency, parallel control of microlitre droplets using automated techniques is essential. Electrowetting-on-dielectric (EWOD), which manipulates droplets using the imbalance of wetting on a substrate, is the most widely employed method. However, EWOD is limited in its capability to make droplets detach from the substrate (jumping), which hinders throughput and device integration. Here, we propose a novel microfluidic system based on focused ultrasound passing through a hydrophobic mesh with droplets resting on top. A phased array dynamically creates foci to manipulate droplets of up to 300 mu L. This platform offers a jump height of up to 10 cm, a 27-fold improvement over conventional EWOD systems. In addition, droplets can be merged or split by pushing them against a hydrophobic knife. We demonstrate Suzuki-Miyaura cross-coupling using our platform, showing its potential for a wide range of chemical experiments. Biofouling in our system was lower than in conventional EWOD, demonstrating its high suitability for biological experiments. Focused ultrasound allows the manipulation of both solid and liquid targets. Our platform provides a foundation for the advancement of micro-robotics, additive manufacturing, and laboratory automation.
Open Access
TOUCHLESS: demonstrations of contactless haptics for affective touch
(ACM, 2023) Chew, Sean; Dalsgaard, Tor-Salve; Maunsbach, Martin; Bergström, Joanna; Seifi, Hasti; Hornbæk, Kasper; Irisarri Erviti, Josu; Ezcurdia Aguirre, Íñigo Fermín; Iriarte Cárdenas, Naroa; Marzo Pérez, Asier; Frier, William; Georgiou, Orestis; Sheremetieva, Anna; Kwarciak, Kamil; Stroiński, Maciej; Hemmerling, Daria; Maksymenko, Mykola; Cataldo, Antonio; Obrist, Marianna; Haggard, Patrick; Subramanian, Sriram; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
A set of demonstrators of contactless haptic principles is described in this work. The technologies are based on electrostatic piloerection, chemical compounds and ultrasound. Additionally, applications related to affective touch are presented, ranging from storytelling to biosignal transfer, accompanied with a simple application to edit dynamic tactile patterns in an easy way. The demonstrators are the result of the Touchless project, which is a H2020 european collaborative project that integrates 3 universities and 3 companies. These demostrators are contactless haptic experiences and thus facilitate the come-and-interact paradigm, where users can approach the demo booth and directly experience the applications without having to wear devices, making the experience fast and hygienic.
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
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
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
Volumetric reach-through displays for direct manipulation of 3D content
(ACM, 2020) Ezcurdia Aguirre, Íñigo Fermín; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Gobierno de Navarra / Nafarroako Gobernua, PI043-2019; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1923
In my PhD, I aim at developing a reach-through volumetric display where points of light are emitted from each 3d position of the display volume, and yet it allows people to introduce theirs hands inside to directly interact with the rendered content. Here, I present TomoLit, an inverse tomographic display, where multiple emitters project rays of different intensities for each angle, rendering a target image in mid-air. We have analysed the effect on image quality of the number of emitters, their locations, the angular resolution and the levels of intensities. We have developed a simple emitter and we are in the process of putting together multiple of them. And what I plan to do next, e.g. moving from 2D to 3D and exploring interaction techniques. The feedback obtained in this symposium will clearly dissipate some of of my doubts and guide my research career.
Open Access
Enhancing the quality of amplitude patterns using time-multiplexed virtual acoustic fields
(American Institute of Physics, 2023) Elizondo Martínez, Sonia; Ezcurdia Aguirre, Íñigo Fermín; Goñi Carnicero, Jaime; Galar Idoate, Mikel; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
Ultrasonic fields can push and levitate particles, heat up materials, induce contactless tactile stimuli, or affect the blood-brain barrier. Current phased-arrays can create dynamic amplitude patterns, but their quality may be insufficient due to the limited density of emitters. On the other hand, passive modulators can provide high quality, but only static patterns can be generated. Here, we show and evaluate how the average of multiple time-multiplexed amplitude fields improves the resolution of the obtained patterns when compared with the traditional single-emission method. We optimize the non-linear problem of decomposing a target amplitude field into multiple fields considering the limitations of the phased-array. The presented technique improves the quality for existing setups without modifying the equipment, having the potential to improve bio-printing, haptic devices, or ultrasonic medical treatments.
Open Access
Electric plasma guided with ultrasonic fields
(American Association for the Advancement of Science, 2025-02-05) Irisarri Erviti, Josu; Ezcurdia Aguirre, Íñigo Fermín; Iriarte Cárdenas, Naroa; Sirkka, Marika; Nikolaev, Dmitry; Mäkinen, Joni; Martinez-Marchese, Alexander; Iablonskyi, Denys; Salmi, Ari; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
Electric plasma forms sparks in midair that transfer electrical current. This current can power high-voltage electronics, kill bacteria, produce tactile sensations, or be used for welding. However, the formation of the spark is chaotic and hard to control. Laser pulses can guide discharges but require high power and are disruptive and cumbersome to control. Here, we show that ultrasonic fields can guide plasma sparks, even around obstacles. The ultrasonic beams can be directed dynamically and within milliseconds, enabling precise, nondangerous, and fast control of high-voltage sparks. This phenomenon can be used for applications in high-voltage switching and plasma treatments.
Open Access
Complex selective manipulations of thermomagnetic programmable matter
(Springer Nature, 2022) Irisarri Erviti, Josu; Ezcurdia Aguirre, Íñigo Fermín; Sandúa Fernández, Xabier; Galarreta Rodríguez, Itziar; Pérez de Landazábal Berganzo, José Ignacio; Marzo Pérez, Asier; Ciencias; Zientziak; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC
Programmable matter can change its shape, stiffness or other physical properties upon command. Previous work has shown contactless optically controlled matter or magnetic actuation, but the former is limited in strength and the latter in spatial resolution. Here, we show an unprecedented level of control combining light patterns and magnetic fields. A mixture of thermoplastic and ferromagnetic powder is heated up at specific locations that become malleable and are attracted by magnetic fields. These heated areas solidify on cool down, and the process can be repeated. We show complex control of 3D slabs, 2D sheets, and 1D filaments with applications in tactile displays and object manipulation. Due to the low transition temperature and the possibility of using microwave heating, the compound can be manipulated in air, water, or inside biological tissue having the potential to revolutionize biomedical devices, robotics or display technologies.