Invited Article: A review of haptic optical tweezers for an interactive microworld exploration

Abstract

This paper is the first review of haptic optical tweezers, a new technique which associates force feedback teleoperation with optical tweezers. This technique allows users to explore the microworld by sensing and exerting picoNewton-scale forces with trapped microspheres. Haptic optical tweezers also allow improved dexterity of micromanipulation and micro-assembly. One of the challenges of this technique is to sense and magnify picoNewton-scale forces by a factor of 10(12) to enable human operators to perceive interactions that they have never experienced before, such as adhesion phenomena, extremely low inertia, and high frequency dynamics of extremely small objects. The design of optical tweezers for high quality haptic feedback is challenging, given the requirements for very high sensitivity and dynamic stability. The concept, design process, and specification of optical tweezers reviewed here are focused on those intended for haptic teleoperation. In this paper, two new specific designs as well as the current state-of-the-art are presented. Moreover, the remaining important issues are identified for further developments. The initial results obtained are promising and demonstrate that optical tweezers have a significant potential for haptic exploration of the microworld. Haptic optical tweezers will become an invaluable tool for force feedback micromanipulation of biological samples and nano- and micro-assembly parts.

Crosstalk elimination in the detection of dual-beam optical tweezers by spatial filtering

“…6,20 Normally, the detection of forces and displacement of objects in multiple optical traps is done by means of a camera, because it has been difficult to separate the signals from the multiple laser beams using photodiodes. With this spatial filtering, it should be possible to separate the signal from each trap and detect it individually with a photodiode, which has distinct advantages over camera detection, e.g., higher temporal and spatial resolution 21,22 as well as easier data analysis. Hence, we believe the presented signal filtering scheme will prove quite useful for future more accurate optical tweezers experiments.…”

Integrated waveguide interferometer with picometric performances

“…The interferometer has been first designed for geophysical applications by the CEA 1 . Its purpose was to obtain a very low noise level and a high dynamic, especially for low frequencies.…”

“…Nowadays, the measurement of the position and the orientation are obviously a main topic for nanometrology. It may concern the positioning of nano-object to manipulate them [1] but also the positioning of macro-object like sample-holder or macro-tools. Resolutions up to the nanometer or tens of picometers are now achieved thanks to the sensors which have been developed.…”

Simultaneous three-dimensional tracking of individual signals from multi-trap optical tweezers using fast and accurate photodiode detection

“…However, in comparison to photodiode detection, this implies reduced spatial and temporal resolution, offline data processing, higher costs and limited axial detection capability. On the positive side, camera based detection easily allows for monitoring many particles in parallel [15][16][17]. To improve the axial detection capabilities of multi-trap camera based imaging, stereoscopic imaging [18,19] and point spread function engineering [20] have been presented.…”