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This paper reports on a bimorph impedance transducer (BIT) which can measure multi-directional translational and rotational impedances in multi-directions. Translational and rotational four-pole models are constructed to describe the dynamic behavior of the transducer. Derived from these models, calibration functions are defined and numerically determined under various boundary conditions. Taking advantage of these functions, point translational and rotational impedance of a structure can be easily and accurately determined by measuring the excitation electrical signals applied to the transducer. To verify the effectiveness of the transducer, a two-dimensional plate is utilized as a test structure. The point impedances of the plate in all its three active degrees of freedom (DOFs) are numerically obtained by the BIT. Through comparing the impedances obtained via BIT with the verification results, it is concluded that the newly designed transducer is accurate in measuring both translational and rotational frequency response functions (FRFs).

Monitoring the ambience's condition is emerging as one of the most important issues in mobile robots. While we need to detect and process the condition quickly and efficiently using sensors, they (sensors) introduce extra complexity to the systems. Therefore this paper aims to develop a new method to simplify the sensing process. It describes an experimental process for monitoring path conditions of a power wheel chair inside and outside of the lab. The monitoring method triggers impedance via transduction matrix of the DC motors which run the wheelchair. The matrix is based on the relationship between electrical and mechanical impedance of the motors. A voltage probe and a current probe are used to monitor the changes of voltage and current supplied to the two DC motors of the system while the wheel chair is moving and the signals are recorded by a Digital Signal Analyzer (DSA). The recorded data are processed by MATLAB and the graphs representing various conditions are plotted. The relationship between the conditions of the path and the changes of voltage, current, and impedance of the motors are listed. The use of the method is justified but miniaturization of the voltage and current probes is necessary for real-life implementation of the system.

Full or partial loss of functionality of the upper limbs is usually associated with strokes, spinal cord injury and many other similar injuries. Traditional rehabilitation treatment however is extremely labor intensive and are usually only available at hospital. However a lot of studies have shown that through the use of repetitive robotic practice can help the patients to recover. In this paper, a 4-bar linkages mechanism is designed and constructed as the upper limb rehabilitation apparatus which provided a set of motions for upper limb rehabilitation and a sensor-less method of assessing the patient arm using motor. The concept of using the input electrical impedance for monitoring the output mechanical impedance is then experimentally tested and justified in experiments.

There are many interfaces in IC packaging, such as that between mold compound and silicon chip, and that between silicon die, die attach and copper lead-frame. The quality of these interfaces has been a critical issue in the reliability testing of IC packaging and during the manufacturing process as the packages become thinner and denser. Common defects such as delamination and crack can be detected using C-mode scanning acoustic microscope with sufficient confidence. However, weak interface due to weak adhesion has often gone undetected and may become potential defective area at a later stage. It is desirable to develop a more quantitative method to characterize the weak interface nondestructively, and this has been the motivation and focus of the study.

Including: 2 parts. Compliant mechanisms provide motion through elastic deformation under the action of external loads. These mechanisms are key functional members in many today's precision machines and devices, such as precision micro-positioning stages, micro actuators, microelectromechanical systems (MEMS) and robots, where micron or even nanometric resolution and accuracy are required for the motion. On the contrary to rigid-body mechanisms, compliant mechanisms consist of monolithic construction without rigid joints or sliders. Thus, they effectively eliminate the wear, backlash, lubrication, and friction problems, which are often encountered by rigid-body mechanisms. Furthermore, their monolithic construction makes the costly assembly process unnecessary and the integration of smart sensors and actuators possible.

There is a strong demand for ultra-high precision positioning devices in many modern precision machines and devices, such as hard disk drives, CD/LD devices, wafer fabrication machines, optical fibre devices and measurement/testing equipment of micro devices. The requirement for resolution or positioning accuracy leaped quantumly from micron level to sub-micron, and subsequently to nano level. In addition to the ever-rising demand for high resolution, there is also strong demand for relatively large range gross motion so that the current two tiers coarse/fine positioning technology can be replaced by the more efficient single tier ultra-precision positioning actuators. Such high precision actuators of nano-level resolution can be made possible by using smart materials based actuators and microelectromechanical system (MEMS) technology.

This report presents the development of MEMS devices for vibration and acoustic sensing and actuation applications under project JT ARC 6/97. In this project, a total of 23 international journal papers and 14 conference papers have been produced. The project was actually kicked off early 1998. We have been working on MEMS devices such as capacitive comb-driven micro-gyroscope, capacitive microphone, floating-electrode-electret-microphone, MEMS GHz micro-switch, ultrasonic transducer, single-chip integrated fluid systems, optical cross-connect switch, and development of lower stress film and bimetallic films for actuation applications.

This report describes the work undertaken under an applied research project that aims to study the dynamic characteristics of the wire bonder, and consists of two major parts, dynamic of ultrasonic transducer and modelling of bonding process RG 28/96