How about 1 mm wide MEMS forceps, at the end of an intravascular catheter, for intracardiac minimally invasive procedures? The research to develop such miniaturized instruments is being conducted by Boston University’s College of Engineering, working together with Children’s Hospital Boston, and Microfabrica, Inc., a California-based microdevice manufacturer.
EFAB™ micro-fabrication technology from Microfabrica is touted to allow the development and commercialization of super-miniature mechanical devices. Here’s a look at the technology:
EFAB technology is an additive microfabrication process based on multi-layer selective electrodeposition of metals. The process is designed to rapidly stack large numbers of independently patterned metal layers on top of each other, allowing designers to create intricate 3-D complex geometries with micron-level precision. EFAB is a batch process like semiconductor manufacturing in which many devices are built simultaneously on wafers, allowing volume production at low cost.
The essence of the approach is a basic three-step process that is used to generate each layer. This is repeated as many times as there are layers to build the desired complex devices. These steps are:
Patterned layer deposition Blanket layer deposition Planarization
In the first step, a layer of metal (the sacrificial metal in this case) is deposited in a pattern corresponding to a cross section of the device to be fabricated.
In the second step, a second material is electroplated onto the substrate, covering the previous layer completely.
Finally, in the third step, the two materials are planarized to yield a single two-material layer.
To continue building the device, the same process is repeated over and over, adding layer after layer until all cross sections of the original 3-D CAD design have been constructed in the desired structural material.
This basic EFAB process used two materials, one structural, and one sacrificial.