Ryan J. Linderman

Atomic layer deposition of conformal dielectric and protective coatings for released micro-electromechanical devices

This paper describes a novel fabrication approach using Atomic Layer Deposition (ALD) of dielectric materials to protect and coat released MEMS devices. The nature of ALD film ensures coverage on all sides of a released MEMS device and is done at a relatively low temperature (down to 150/spl deg/C). The ALD film thickness can be precisely controlled as each reaction cycle deposits approximately one monolayer of atoms. To demonstrate the concept of conformal layer deposition, alumina (Al/sub 2/O/sub 3/) was deposited onto released MEMS devices prior to electrostatic testing. Curvature and increase in beam stiffness for coated MEMS devices were investigated.

Solder self-assembled micro axial flow fan driven by a scratch drive actuator rotary motor

This work presents the first micro-sized axial flow fan driven by a scratch drive actuator rotary motor. The eight fan blades are mass assembled using the surface tension of molten 4 mil diameter 63 Sn/37 Pb manufactured solder spheres. A sample size of 27 blade angles was measured with a mean assembly angle of 107.24/spl deg/. The actual mean of the manufactured solder sphere diameters was measured at 4.89 mils, yielding a, model predicted, mean blade assembly angle of 107.71/spl deg/. At resonance, the SDA motor can be driven at 50 RPM forward with a 2 kHz AC voltage of 30 V/sub 0.P/, and at 100 RPM reverse with a 3 kHz signal. For non-resonant frequencies, the SDA motor can be driven in a forward direction with linear speed control up to 180 RPM using driving signals from 75-150 V/sub 0.P/. Fluid movement by the fan was also experimentally demonstrated.

The resonant micro fan gas pump for active breathing microchannels

This paper reports on the fluidic and mechanical performance of the resonant micro fan as an in-channel gas pump. Experiments with resonant fan arrays assembled within test channels were performed in order to observe the effects of changing fan length and resonant frequency with respect to volumetric flow rate in the channel. Flow rates of approximately 10 /spl mu/l/min were produced by single fans with the flow increasing to 25 /spl mu/l/min for three fans operated simultaneously in the same channel (the capability exists for many fans to be arrayed in a microchannel system). The ability of the micro fan to collect airborne suspended smoke particles was also experimentally examined.