We've recently built a highly miniaturized Arduino (pictured below) that may be interesting to some of the members of this forum. It's in the form of a 10mm x 10mm x 1.5 mm encapsulated module attached to a 25 conductor polyimide flex cable with conductor pitch of 0.3mm.
The module includes an Atmega 328P chip with a 2.8v LDO regulator, an inverter that is useful for interrupt management, a dedicated I2C interface, an SPI interface and several other digital and analog I/O options. Schematics and an Eagle layout are available at www.potomacmeso.com. We built this setup for wireless sensing applications, but it probably would be useful in other areas where miniaturization is important. If there is enough interest, we may offer this as a product. Right now we're comp'ing a few of these to advanced users with miniature applications.
Thanks for all of the comments. These are all good.
A bottom view of the 10mm x 10 mm active module is shown in the attachment. The connection pads are the staggered arrays on the left and right sides of the package. The module resembles a big surface mount chip and there's more room inside for other components. We've also built sensor arrays in the same modular format.
In some ways these modules are like big ASIC's that can be mounted in several ways. The second attached photo shows top and bottom views of a complete wireless sensor built around an Arduino module and an accelerometer module. We used a 2.4GHz wireless module from Anaren here. If anyone is interested in the Anaren/Arduino interface firmware we've posted it at www.potomacmeso.com and also on Github.
Thanks for the feedback.
I'm looking into ways to make the download a little smoother. In the meantime, try right clicking on the download link and selecting "Save target as...". After saving, change the file extension from .xml to .brd. Then you should be able to open it with the v6 versions of Eagle. This works on my system. Let me know if you continue to have problems.
We aren't selling these yet, but, if you have an application that needs a miniature Arduino, send me a note at www.potomacmeso.com/contact. I'll try to get you something to work with.
We use a laser-based process in which narrow grooves and holes are engraved in a thin substrate and filled with nanoparticle silver paste that cures to solid silver at moderate temperatures. Typical conductor widths are 15 micrometers. These narrow conductors are easy to route between pads and under components to make miniature circuit modules using the smallest surface mount components. Connections to the silver conductors are made with conductive epoxy.
There is more detail on the module fabrication process in the publications on the download page at potomacmeso.com. No photolithography or etching is involved and no lead is used so the process is pretty green.
Yes, but we would first like to get more input from various kinds of users about what they need inside the miniature modules (MCU type, regulators, sensors, op amps, memory, etc.) and how they would like to connect to it (connectors, cable, solder contacts to a board, epoxy contacts to a board, etc.). Comments and suggestions are always appreciated, either here or through our website, www.potomacmeso.com.
I have some project ideas, but am too new to the technology to answer the requirements question with enough confidence to make it worthwhile. I'll definitely watch with interest.