Pixie dust

Abstract

Figure 1: Application images of Pixie Dust, levitated and manipulated objects in graphic metaphors. (a) Floating screen with projection. (b-c) Whale (hung by string) with particles and projected spout. (d) Physical vector graphics (showing "heart"). (e) Physical raster graphics. AbstractWe propose a novel graphics system based on the expansion of 3D acoustic-manipulation technology. In conventional research on acoustic levitation, small objects are trapped in the acoustic beams of standing waves. We expand this method by changing the distribution of the acoustic-potential field (APF). Using this technique, we can generate the graphics using levitated small objects. Our approach makes available many expressions, such as the expression by materials and non-digital appearance. These kinds of expressions are used in many applications, and we aim to combine them with digital controllability. In the current system, multiple particles are levitated together at 4.25-mm intervals. The spatial resolution of the position is 0.5 mm. Particles move at up to 72 cm/s. The allowable density of the material can be up to 7 g/cm 3 . For this study, we use three options of APF: 2D grid, high-speed movement, and combination with motion capture. These are used to realize floating screen or mid-air raster graphics, mid-air vector graphics, and interaction with levitated objects. This paper reports the details of the acoustic-potential field generator on the design, control, performance evaluation, and exploration of the application space. To discuss the various noncontact manipulation technologies in a unified manner, we introduce a concept called "computational potential field" (CPF).

Point-and-Shake

“…This approach offered limited control over object position, but was scalable to levitate multiple objects. Pixie Dust [15] used acoustics to levitate objects: arrays of ultrasound transducers created an inaudible sound field that 'trapped' the objects. This supported larger numbers of smaller objects ( 1-5mm) positioned close together (at least 4.5mm apart).…”

“…Interaction with the systems discussed has been limited to moving a single levitating object, either by grasping it [13,23] or mapping it to hand position [15,17]. 'Hands on' grasping interactions are not possible with acoustic levitation and are also unsuitable for levitations with several mid-air objects (e.g., the many data points in Floating Charts [18]), because the levitated objects may be too small to grasp and position correctly, they may be out of reach, or they may be inaccessible behind other objects in the physicalisation.…”

“…'Hands on' grasping interactions are not possible with acoustic levitation and are also unsuitable for levitations with several mid-air objects (e.g., the many data points in Floating Charts [18]), because the levitated objects may be too small to grasp and position correctly, they may be out of reach, or they may be inaccessible behind other objects in the physicalisation. Existing mid-air interactions [15,17] have demonstrated how a single object might be translated with hand movements, but have not addressed how to create complete and usable interactions with such levitated objects (e.g., initiating interaction, selecting a target object, and ending the interaction). In this paper, we investigate object selection as a fundamental part of interaction with levitating objects and we demonstrate the first complete interaction technique with a levitating object display.…”

“…Research into the technical challenges of levitation has led to novel methods involving magnets [13], airflow [1,23] and acoustics [14,15,17], moving us closer to applications like those described earlier. Acoustic levitation, in particular, has benefited from recent work [14,15,17,20] and many objects can now be levitated and moved independently.…”

“…Acoustic levitation, in particular, has benefited from recent work [14,15,17,20] and many objects can now be levitated and moved independently. Research is now required to establish the interaction techniques needed to manipulate such displays.…”