This paper investigates the reaction of a living insect to electric stimulation. Artificial electrical stimulation is one of the tools of neuroethology to investigate the neural system. By creating artificial inputs to the system, specific reaction can be observed. The escape turn is a well-known reaction pattern of an insect in response to the appearance of a predator. In the first part we analyze the locomotory reaction of an insect (Periplaneta Americana) to various electrical stimuli. These stimulus-reaction measurements are done on a light-weight styro-foam trackball which is connected to a computer. This allows us to record the turning rate and the forward movement of the insect in response to antennal stimulation. Based on this data a simple mathematical model is established. As a simple example of an autonomous bio-robotic system and to verify the black-box model an electronic backpack which does line-tracking has been built. Using two photosensors as inputs the electronic backpack forces the insect to walk along a black line.

Two different principles for actuation of microactuators, the Lorentz force and the Coulomb force, are combined on the same device. Microactuators are fabricated using conventional semiconductor technologies. The actuator patterns are etched out from a 1 /spl mu/m Al thin-film on a Si wafer. A simple model of an electrostatic actuator, for parallel electrodes, is introduced. If this actuator performs work against a spring, the displacement versus voltage executes a hysteresis curve. In the present paper the combination of Lorentz force and Coulomb force produces actuation forces in all 3 spatial directions (x, y, and z), and as an application example an xyz-table was built.

Microcoils are less efficient due to the scale effect, but if a permanent magnet is used, the result is a quite scale-independent magnetic field strength. 2D-microstructures of various shapes have been etched out from a 1 /spl mu/m aluminium thin-film. These structures are locally released from the wafer by undercut etching. By sending an electric current through them, a Lorentz force component is induced in some sections, resulting in deformation of the thin-film structure. First, different shapes of 1-turn coils are presented. The arrangement of vertical and parallel magnetic field is discussed. Micromachine fabrication using IC thin-film, lithography and etching technology is presented. An x-y table was built as an application example for the use of Lorentz force in micromachines. For protection and the ease of handling the microactuators are packaged into a standard IC case. As examples of further applications of Lorentz force actuators, a micromirror device, a ciliary motion system and microrelays are discussed.