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.
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
Generating airborne ultrasonic amplitude patterns using an open hardware phased array
(MDPI, 2021) Morales González, Rafael; Ezcurdia Aguirre, Íñigo Fermín; Irisarri Erviti, Josu; Andrade, Marco A.B.; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Gobierno de Navarra / Nafarroako Gobernua
Holographic methods from optics can be adapted to acoustics for enabling novel applications in particle manipulation or patterning by generating dynamic custom-tailored acoustic fields. Here, we present three contributions towards making the field of acoustic holography more widespread. Firstly, we introduce an iterative algorithm that accurately calculates the amplitudes and phases of an array of ultrasound emitters in order to create a target amplitude field in mid-air. Secondly, we use the algorithm to analyse the impact of spatial, amplitude and phase emission resolution on the resulting acoustic field, thus providing engineering insights towards array design. For example, we show an onset of diminishing returns for smaller than a quarter-wavelength sized emitters and a phase and amplitude resolution of eight and four divisions per period, respectively. Lastly, we present a hardware platform for the generation of acoustic holograms. The array is integrated in a single board composed of 256 emitters operating at 40 kHz. We hope that the results and procedures described within this paper enable researchers to build their own ultrasonic arrays and explore novel applications of ultrasonic holograms.
Open Access
Smarterial – Smart matter optomagnetic
(2021) Irisarri Erviti, Josu; Marzo Pérez, Asier; Galarreta Rodríguez, Itziar; Estatistika, Informatika eta Matematika; Ingeniaritza; Zientziak; Institute of Smart Cities - ISC; Institute for Advanced Materials and Mathematics - INAMAT2; Estadística, Informática y Matemáticas; Ingeniería; Ciencias
Smart materials, also known as programmable materials, are a combination of different components that have the capability to change shape, move around and adapt to numerous situations by applying an external controllable field. Previous works have used optically guided matter or magnetically actuated materials, but similarly to soft robots, they are limited in spatial resolution or strength. Here we propose combining a low temperature thermoplastic polymer Polycaprolactone (PCL) with ferromagnetic powder particles (Fe). Focused light can heat this compound at specific locations and make it malleable. These heated spots can be actuated by external magnetic fields. Once the material cools down, this process can be repeated, or reversed. The compound can be actuated contact-less in the form of 3D slabs, 2D sheets, and 1D filaments. We show applications for reversible tactile displays and manipulation of objects. The laboratory team has characterised the density, weight, magnetic attraction, magnetic force, phase change, thermal and electrical conductivity and heat difusión (spread point test) for smart ferromagnetic compounds of different mixture proportions. The main advantages of this smart matter optomagnetic are the high spatial resolution of light and the strong force of magnetic attraction whilst mechanical properties of polymers are practically conserved. Due to the low temperature required and the possibility to use infrared or electromagnetic induction to heat the compound, the smart material can be used in air, water, or inside biological tissue. Eventually, Smart materials will enrich collaborative movements, such as grab and hold, and more complex ones, as reshaping and reassembling.
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
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
Novel contactless haptic technologies for creating affective tactile sensations when interacting with computer systems
(2025) Irisarri Erviti, Josu; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Gobierno de Navarra / Nafarroako Gobernua
Esta tesis doctoral desarrolla y explora nuevas tecnologías hápticas sin contacto para generar sensaciones táctiles en los usuarios a distancia y sin obligarles a llevar dispositivos. De esta forma, se reduce el tiempo de empezar a usar el sistema y se mejora la disponibilidad a utilizar dispositivos públicos. Utilizando hápticas sin contacto, esta tesis también quiere ir más allá del tacto funcional (p.ej., notificaciones o discriminación de objetos) e intenta reproducir algunas experiencias perdidas en entornos virtuales como el tacto afectivo. Por ejemplo, los movimientos de roce en el antebrazo pueden tener un fuerte significado afectivo (caricias) pero la tecnología de ultrasonidos focalizados actual no estimula con suficiente intensidad estas áreas de piel. Sin embargo, otras tecnologías sin contacto, como la luz infrarroja o la electrostática podrían generar estas sensaciones afectivas. Los sentidos visual y auditivo han dominado los sistemas de interacción humano-ordenador, a veces desatendiendo el sentido del tacto. En este trabajo, se presentan tecnologías hápticas que pueden proporcionar sensaciones táctil a distancia. Tienen el potencial de mejorar las experiencias inmersivas en entornos virtuales, así como de facilitar una conexión más profunda entre sus usuarios. Esta tesis también explora brevemente el uso de la háptica sin contacto para experiencias multimodales, tecnologías sin contacto y computación afectiva. En primer lugar, la tesis desarrolla una técnica híbrida, un material inteligente que es una combinación de termoplástico y polvo de hierro que se puede activar a distancia mediante calor y campos magnéticos, pero el usuario sigue necesitando contacto directo con el material. Se pensó que este sistema sería la base para comparaciones. En segundo lugar, se presenta una demostración utilizando electrostática para crear piloerección en el antebrazo. Esta tecnología puede actuar a distancia y tiene el potencial de crear estímulos afectivos. En tercer lugar, se combinan el plasma eléctrico y el ultrasonido para guíar chispas eléctricas en el aire, capaz de generar estímulos fuertes y con una buena resolución espacial y temporal. Finalmente, se explican combinaciones aún inacabadas de tecnologías; como ultrasonido, electrostática, chispas eléctricas, aerosoles, luz infrarroja, cambio de humedad/temperatura, aire y láseres. Espero que este trabajo sirva para introducir otras tecnologías hápticas sin contacto distintas de los ultrasonidos, que ha sido la tecnología dominante en la última década. Tener disponibles más tecnologías hápticas sin contacto, puede motivar la incorporación de feedback táctil en algunos sistemas de interacción entre humanos-computadoras, como las experiencias interactivas públicas en exposiciones, museos o teatros.