Omnidirectional microscopy by ultrasonic sample control

Abstract

Omnidirectional microscopy (OM) is an emerging technology capable of enhancing the threedimensional (3D) microscopy widely applied in life sciences. In OM, precise position and orientation control of the sample are required. However, current OM technology relies on destructive, mechanical methods to hold the samples, such as embedding samples in gel or attaching them to a needle to permit orientation control. A non-contacting alternative is to levitate the sample. Up until now levitation methods have lacked orientation control. We enable omnidirectional access to the sample by introducing a method to control acoustic levitation that provides precise orientation control. Such control around three axes of rotation permits rapid imaging of the sample from any direction with a fixed camera and subsequent 3D shape reconstruction. The control of non-spherical particles is achieved using an asymmetric acoustic field created with a phase-controlled transducer array. Our technology allows robust 3D imaging of delicate samples and their study in a time-lapse manner. We foresee that the described method is not limited to microscopy and optical imaging, but is also compatible with automated sample handling, light-sheet microscopy, wall-less chemistry, and non-contacting tomography.

Simulating Acoustic Orientation Trapping for Stable Levitation

“…We recently developed an acoustic levitation method capable of full 3-axis orientation control of asymmetric samples [6]. This was achieved with a spatially asymmetric vortex trap created with PAT, whose phases and amplitudes were set according to our method.…”

A Non-Contact Manipulation for Robotic Applications: A Review on Acoustic Levitation

“…The control of acoustic levitation process in all of its stages had seen some traditional control strategies which applied to achieve the desired performance, but it has not yet been proven that an object can be rotated in three dimensions under control. A comprehensive control over the orientation in three dimensions for a non-spherical object only by accurately aligned the acoustic trap using a devised algorithm, and a phased-array transducer (PAT)-based levitator was created specifically for this study demonstrated by [171] which would allow implementations in spectroscopy, photogrammetry, and contactless placement. Up to now, the orientation has only been controlled in one dimension according to [140], [161].…”

Position and Orientation Control of Complex-Shaped Samples in Acoustic Levitation

“…The 3D orientation control can be used to handle fragile samples and therefore has applications in industry and medicine. The applications vary from contactless 3D imaging [4] to moving electronic components [5].…”