Sonolithography is the process of directed patterning of airborne particles through the exertion of acoustic radiation forces in ultrasound fields. In this work we present a novel way to explore and gain intuition about the process through tangible interaction. We demonstrate the design and use of a physical instrument for the creation of sonolithographs. The design includes the “Orbograph”, a tangible controller that embodies key acoustic parameters through direct tactile interactions; a low-cost and open-source driving circuit; and a configurable transducer array. We demonstrate its capabilities by presenting sonolithographs made with the tool that contain linear patterns, grids, circular and more complex shapes. By using different dyes and active materials, we demonstrate sonolithography's creative application as well as suggest its potential in the fabrication of interactive devices. Through this work we encourage a playful artistic exploration of the domain to motivate future research in sonolithography for tangible material interactions.

A magnetically controlled steerable robot with the capability of flexible navigation and intraoperative ultrasonic imaging and position sensing in neurosurgery is introduced in this paper. The robot system uses a piezoelectric transducer as the ultrasonic imaging beacon and applies a permanent magnet as the actuation unit, which can steer the flexible robot following a planned complex path to access a target in the brain. In order to enable the robot to navigate flexibly within tissues, a method is proposed to enhance magnetic actuation force by utilizing an array of small magnetic blocks instead of using a large magnet. The improvement of the array for magnetic field distribution was verified by simulation. Simulation studies also involved modeling the ultrasonic transmitting and receiving functions of the piezoelectric transducer to verify the feasibility of using them for intraoperative imaging. In addition, a prototype of the robot is fabricated and tested. The feasibility of the proposed magnetically controlled steerable robot for navigation in soft tissue is verified.

Minimally invasive surgeries (MIS) or natural orifice transluminal endoscopic surgeries (NOTES) such as the transurethral resection of bladder tumor (TURBT) require the surgical robot to be miniaturized to perform surgical procedures in confined spaces. However, the surgical robot's tiny size poses problems in its fabrication and shape sensing. In this paper, a miniature continuum surgical robot is proposed with a unique laminated structure which can be fabricated through a 2D lamination process and converted into 3D through folding. This multi-material laminated structure also facilitates the integration of tiny piezoelectric transducers on the robot's surface as beacons to generate ultrasonic waves for shape detection. A novel beacon total focusing method (b-TFM) algorithm is developed to process the received ultrasonic data and create a high-quality ultrasonic image from which the shape of the continuum robot can be extracted. The proposed robot and the ultrasonic shape detection method are validated through simulations and experiments. The error in the open-loop trajectory control is less than 4 mm without compensation, and the error in the ultrasonic shape detection is less than 1 mm. This confirms the possibility of improving the trajectory control accuracy by using the detected shape as a feedback for closed-loop control.

Centuries of development in optics have given us passive devices (i.e. lenses, mirrors and filters) to enrich audience immersivity with light effects, but there is nothing similar for sound. Beam-forming in concert halls and outdoor gigs still requires a large number of speakers, while headphones are still the state-of-the-art for personalized audio immersivity in VR. In this work, we show how 3D printed acoustic meta-surfaces, assembled into the equivalent of optical systems, may offer a different solution. We demonstrate how to build them and how to use simple design tools, like the thin-lens equation, also for sound. We present some key acoustic devices, like a "collimator", to transform a standard computer speaker into an acoustic "spotlight"; and a "magnifying glass", to create sound sources coming from distinct locations than the speaker itself. Finally, we demonstrate an acoustic varifocal lens, discussing applications equivalent to auto-focus cameras and VR headsets and the limitations of the technology.

The ability to control acoustic fields offers many possible applications in loudspeaker design, ultrasound imaging, medical therapy, and acoustic levitation. Sound waves are currently shaped using phased array systems, even though the complex electronics required are expensive and hinder widespread use. Here we show how to control, direct, and manipulate sound using 2-dimensional, planar, acoustic metasurfaces that require only one driving signal. This offers the advantages of ease of use and versatility over currently available phased arrays. We demonstrate the creation of a haptic sensation and steering of a beam produced by a parametric speaker. This simple, yet highly effective, method of creating single-beam manipulators could be introduced in medical or manufacturing applications.

The screen in our laptops or the white surface of a projector screen are common examples of displays that we use in our daily life to visualize information. Here, we propose to use levitated particles above these displays to enrich the presented information. By means of acoustic or magnetic levitation we show that it is possible to move a particle in mid-air in the space above these displays. We present different configurations that are feasible with current technology, as well as use cases. In this demo, the visitors will be able to explore and interact with various levitators integrated with traditional displays.

We present two realizations of TastyFloats, a novel system that uses acoustic levitation to deliver food morsels to the users' tongue. To explore TastyFloats' associated design framework, we first address the technical challenges to successfully levitate and deliver different types of foods on the tongue. We then conduct a user study, assessing the effect of acoustic levitation on users' taste perception, comparing three basic taste stimuli (i.e., sweet, bitter and umami) and three volume sizes of droplets (5μL, 10μL and 20μL). Our results show that users perceive sweet and umami easily, even in minimal quantities, whereas bitter is the least detectable taste, despite its typical association with an unpleasant taste experience. Our results are a first step towards the creation of new culinary experiences and innovative gustatory interfaces.

We introduce UltraHaptics, a system designed to provide multi-point haptic feedback above an interactive surface. UltraHaptics employs focused ultrasound to project discrete points of haptic feedback through the display and directly on to users' unadorned hands. We investigate the desirable properties of an acoustically transparent display and demonstrate that the system is capable of creating multiple localised points of feedback in mid-air. Through psychophysical experiments we show that feedback points with different tactile properties can be identified at smaller separations. We also show that users are able to distinguish between different vibration frequencies of non-contact points with training. Finally, we explore a number of exciting new interaction possibilities that UltraHaptics provides.