Defence Science and Technology Organisation (DSTO) has developed a low power RS485 sensor network that can be
hardware configured at design time from a number of modules, depending on its final application. The core predesigned
module includes network communications, microprocessor control and digital input/output. A number of analogue
sensor interface modules can easily be added to this core. In addition, the software is also of modular design consisting
of a set of core operating routines and a set of routines for controlling sensor operations that can be downloaded or
upgraded in the field. Prime consideration in this development has been given to the need for small size, low weight, low
power and versatility of operation. The hardware is based around the Texas Instruments MSP430® micro-controller. This
paper will present some of the considerations leading to the design and examples of applications of the sensor network.
Defence Science and Technology Organisation (DSTO) is engaged in the development of sensor systems to monitor the
environment and condition of high value structures and machinery. The development of this technology promises to
contain escalating costs associated with the through-life support of major capital platforms, including high-rise
buildings, bridges, aircraft, ships and offshore oil/gas structures. As part of this work a laser micromachining process for
fabricating thin foil sensors has been developed. Laser micromachining has some inherent advantages over other
processes such as metal deposition and chemical etching for the production of thin foil sensors. A chief advantage of the
process is the ability to make relatively thick (100 µm) micro-patterned sensors (20 µm features) out of a very wide
variety of metals with only minor changes to the process. This last feature makes feasible the manufacture of sensors
out of the same material as the bulk structure that is being monitored. This paper presents results for some laser micromachined
thin foil corrosion and environmental sensors and compares these with similar sensors made using different
Recent advances in UV laser machining have allowed the development of accurate and rapid prototyping of micro scale
devices. Two examples are presented of how modern UV laser micro machining may be applied to novel applications in
engineering research and the development of state of the art micro sensors for structural health monitoring. We also
show how micro device development is now a rapid process where novel procedures allowing the manual handling of
work pieces may be used to make two layer laser machined devices with alignment to tens of microns.
Thin metal foil sensors for corrosion monitoring are being developed for applications under paints, sealants and in lap joints. These sensors are two electrode electrochemical devices. A fundamental consideration for these sensors is that they reflect the corrosion activity of the structure to be monitored. To this end, fine milling, chemical etching and laser micromachining are used to fabricate the sensors from the same material as the structure of interest. Details of the fabrication, characterisation and micro-circuit instrumentation of the sensors will be presented.
UV Laser micro-machining of metals for the production of micro devices is generating significant interest. This approach to micro-fabrication has the distinct advantage of being non-contact, rapid, flexible and precise. At present, the laser micro-manufacture of new micro device designs, or the introduction of untried materials requires exploration of laser parameters to achieve acceptable yields. We have undertaken a quantitative study of UV laser micro-machining of 2024 Aluminium, Copper and marine grade steel. These metals are of broad application in the manufacture of sensors for structural health monitoring and are of particular interest to defence. The UV laser micro-machining study was carried out using a frequency tripled Nd YAG laser. In this paper the influence of the number of passes of the laser over the metal surface are compared with cutting profiles, and ablation or melt behaviour as a function of cut depth.