This special issue on Micro/Nano Robotic Perception, Control and Manipulation describes several complementary research efforts from Asia, the United States, and Europe. The topic is timely and the work published in this special issue shows how traditional robotics research is contributing to the emerging micro and nano technologies that are already beginning to demonstrate a strong impact on our society. At milli to microscales, three research efforts in inspection and microassembly are presented. From the University of Minnesota, a force controlled microgripper for photonics microassembly applications is presented. Another important aspect of microassembly is the tracking and alignment of microparts using vision feedback. Work by Dr. Yesin at the Swiss Federal Institute of Technology-Zurich (ETHZ) is directed towards using CAD model-based full 3DOF tracking for closed-loop control of automated microassembly. Moving towards submicron and nano scales, work from the University of Oldenburg in Germany in developing a novel platform for nanohandling using mobile microrobots has given rise to interesting concepts in how systems that perform future nanomanipulation tasks may be configured. A paper co-authored by researchers at the University of California-Berkeley and Carnegie Mellon University considers the use of optical tweezers integrated with chemical linkages for manufacturing 2D and 3D structures at micro and nanoscales. A microbial separation system at the University of Nagoya uses a novel touch sensor and a micropipette, and demonstrates the interesting research problems that exist in the rapidly emerging field of BioMicroRobotics. It is clear that micro/nano robotics research efforts, like those presented in this special issue, represent a key component of robotics studies, and illustrate one direction where robotics must head in order to ensure that the field of robotics remains relevant to science, engineering and society as a whole.

Photonics is a field that straddles both the macro and micro worlds. It largely deals with macro-scale devices, but many of these require sub-micron-scale precision in assembly. This makes it a very interesting application domain. We describe a microgripper for microassembly of photonic devices and micro-exploration of the properties of sub-micron attachment means (such as solder and UV epoxy). The microgripper has multi-degree-of-freedom actuation and a unique micro/macro actuator on the gripping axis to facilitate human loading and unloading and also very precise accommodation. We demonstrate the force sensitivity and stiffness of approximately 20 mN and 70 mN/um, respectively to be sufficient for the intended tasks. Finally, we demonstrate the gripper accommodating forces of a large solder ball freezing and cooling as a prelude to our intended study of sub-millimeter solder balls in sub-second heating regimes.

We present a visual feedback method for closed loop control of automated microassembly. A CAD model based multi-camera visual tracking system that is well suited for flexible automation and assembly of complex 3D geometries was developed. The system is capable of providing six degree-of-freedom pose feedback on the observed micro-components in real-time (30 Hz). Using CAD models of the observed objects, a complete description of the observed scene, including the effect of occlusions, is available and dependence on distinctive visual features such as fudicial marks is avoided.

Special micromanipulators are needed to manipulate very small objects. Most micromanipulators are specialized to perform a task they are designed for, but are too inflexible to adapt to other problems. Therefore, flexible newly developed mobile microrobots are presented with precision in the sub-micrometer range while offering a macroscopic workspace. The main parts of each mobile microrobot, the mobile platform, the manipulator and end effectors, are explained in detail, with some experimental data given.

The new driving principle of the mobile platform allows high resolution, low energy consumption, which makes an on-board power supply feasible and a maximum velocity of several mm/s.

Useful human interfaces are needed for a successful teleoperation. The most important interface next to the vision feedback is a haptic interface. The paper presents a newly developed haptic interface for a micromanipulation station. The mechanical design and the design of the control system of the haptic interface are discussed in details. The control architecture of the micromanipulation station and the integration of the haptic device into the micromanipulation station are presented.

Optical tweezers have been used as versatile tools for non-contact manipulation of micrometer-sized entities. This paper proposes a hybrid micro/nanoscale manufacturing system using optical tweezers and chemical linkages for fabricating 2D and 3D micro/nanostructures. A holographic multiple trap optical tweezers system is first used to trap particles in a desired pattern. The particles are then connected to form rigid units using suitable chemistry. Connection schemes based on gold seeding, complementary-DNA linkage and streptavidin-biotin chemistry are presented and possible applications of this technique are explored. This method combines the advantages of top-down and bottom-up approaches and is compatible with organic and inorganic materials.

Isolation and separation of the target microbe or cell from a large heterogeneous population is quite important. We propose a new touch sensor that is used for the separation of the target microbe with a pipette. This sensor is sensitive enough to protect the fragile pipette tip from abrupt collision. Using this sensor, we developed a novel separation system for screening a target microorganisms from the randomly distributed samples in the dish with the local viscosity control of the thermosensitive hydrogel. With this system, the target yeast cell was extracted successfully.

Researchers from the Japanese company Toyota have designed and patented a motor car that, they claim, expresses emotions. They say that the car is able to laugh, cry or show anger and is also capable of singing to its occupants.

A fuzzy logic controller for an omni-directional, autonomous guided vehicle (AGV) implementing Mecanum wheels to achieve directional control of its motion is presented. Omni-directional robotic platforms advantage over conventional designs is that they are capable of performing tasks in congested environments. The AGV's behaviour during navigation is controlled using a fuzzy logic controller, with slip detection.

This paper describes a micro-optical three-axis tactile sensor capable of sensing not only normal force, but also shearing force. The normal force was detected from the integrated gray-scale values of bright pixels emitted from the contact area of conical feelers. The conical feelers were formed on a rubber sheet surface that maintains contact with an optical waveguide plate. The shearing force was detected from horizontal displacement of the conical feeler. In the experiments, a precise multi-axial loading machine was developed to measure sensing characteristics of the present sensor. Results show that the normal force was specified uniquely under combined force conditions and that the shearing force was specified by modifying the relationship between the shearing force and the horizontal displacement on the basis of normal force. We formulated a set of expressions to derive the normal force and the shearing force by taking into account this modification. Furthermore, calibration coefficients were identified for transforming the integration of gray-scale values into the normal force and for transforming the horizontal displacement into the shearing force. This result suggests that the expressions can estimate the normal force and the shearing force in wide-load regions.

This paper discusses the techniques and their applications in the development of a path planning system composed of three modules, namely: global vision (GVM), trajectory planning (TPM) and navigation control (NCM). The GVM captures and processes the workspace image to identify the obstacle and the robot configurations. These configurations are used by the TPM to generate the Voronoi roadmap, to compute the maximal clearance shortest feasible path and the visibility pathway between two configurations. The NCM controls the robot functionalities and navigation. To validate the path planning system, three sets of experiments have been conducted using the Lab robot Khepera, which have shown very good results.

This paper proposes an efficient algorithm for computing finger forces involved in a three-dimensional objects grasp. Effective finger force computation is necessary for the successful manipulation on an object by a multifingered robot hand. Based on previous works, the stability forces are computed as a solution of an optimization problem. This optimization problem is mapped into a linear quadratic problem under inequality constraints. We propose a new approach for this problem: the problem is solved as a minimal distance calculation problem in the forces space. The results obtained by simulation demonstrate the efficiency and the numerical stability of the method. This method is used with the LMS mechanical hand as a component of the global control strategy dedicated to the object manipulation.

Most nonlinear control concepts used in robotics are based on a more or less accurate inverse model of the robot. In contrast to this, the design and properties of a general $n$-loop control structure based on a divided forward model of the robot, the so-called multi-loop Model Following Control Structure ($n$-MFC), is presented in this paper. Its theoretical basics and its concept are explained. The stability and robustness of the proposed control structure is analyzed. The theoretical assumptions are verified in many experiments with a two-joint robot manipulator. Qualitative as well as quantitative results of the experiments are presented and discussed.

An ultra-precision integrated robotic system is developed, which integrates a passive robotic measurement system (shadow system) with an industrial robot. The shadow system is built almost ideal. In a working process, when the end-effecter of integrated robot is driven to a target with errors which are caused by degrading factors associated with the robot, the shadow system will independently detect the end-effecter frame instantly with ultra-precision kinematic accuracy. A scheme of approach control is then established to drive the end-effecter of the integrated robot to compensate the error step by step until the desired target is achieved with ultra-precision positioning accuracy.

Control systems of robot manipulators offer many challenges in education where the students must learn robot dynamics and control structures, and understand relations between the control parameters and the systems performance. Interactive simulation is aimed at improving the understanding of and intuition for the abstract parts of the control of robot courses. This paper presents an application of interactive simulation to teach control systems of robots. The application considers a nonlinear robot arm and two control modules: position control and motion control. Students can directly manipulate graphical representation of the systems such as a choice among seven control structures, controller gains, and desired trajectories, and obtain instant feedback on the effects. These features make the interactive learning tool stimulating and of high pedagogical value.

The determination of the assembly modes of the parallel structures with three legs of type PS or SP (P and S stand for prismatic pair and spherical pair, respectively) consists of solving the direct position analysis of all the three-legged parallel manipulators which have, in each leg, one not actuated prismatic pair, one not actuated spherical pair and one or two one-dof actuated pairs of any type, placed along the leg in any order. There are two types of such structures: (i) 3PS structures and (ii) SP-2PS structures. The procedure to determine the assembly modes of the SP-2PS structures has not been presented yet, in the literature. This paper presents the analytic form determination of the assembly modes of the SP-2PS structures. In particular, the closure equations of a generic SP-2PS structure will be written and their solution will be reduced to the solution of an eight-degree univariate polynomial equation with real coefficients. Finally, the proposed algorithm will be applied to a real case. The result of this study is that the assembly modes of any SP-2PS structure are at most eight, and the end-effector poses, which solve the direct position analysis of the parallel manipulators that generate those structures, are also eight.

Autonomous mobile robot navigation systems are based on three principal kinds of techniques: map-based navigation, map-building-based navigation and mapless navigation. We propose a mapless method for trajectory description in unknown indoor environments. The method uses distance measurements from a 2D laser range finder, digitises the robot's visibility area, eliminates superfluous data and reorients their presentation with laws similar to those used in cellular automata. The landmarks are extracted and organised in a panoramic description called fresco. The frescoes which are validated by means of neighbourhood rules. The most informative frescoes are detected by means of two criteria and stored. The stored frescoes are considered as a human-like descritption of the robot's route and could be used by the robot to retrieve its route to its starting point.