Archive for February 8th, 2007

Nanotech Biological Sensors Become Easier to Build

Thursday, February 8th, 2007

Nanowires carved from silicon detect small traces of protein and might be amenable to mass production
By JR Minkel

Call it the easy-bake nanosensor. Researchers report they have built an exquisitely sensitive biological detector from silicon using conventional tools, meaning it could in principle be mass-produced.

Relying on standard materials and manufacturing techniques would make it much easier to incorporate a nanosensor with the electronics inside a handheld device, says chemist Mark Reed of Yale University, co-author of a report in this week’s Nature detailing the technology. “This has the ability to scale in power and cost, just like regular electronics,” he says.

Reed and his colleagues coated their 30-nanometer-wide wires in antibodies or other biological molecules capable of latching onto certain proteins. These receptors plucked their matching proteins from a solution washed over the sensor, which detected the change because the electric charges on the amassed proteins easily disrupted the current flowing through the wires. Reed likens the effect to the way that stepping on a flimsy garden hose (but not a tough fire hose) would block its flow.

The device detected as few as 30,000 free-floating proteins in a cubic millimeter of fluid in a matter of seconds, which Reed says compares favorably with other nanowire sensors. It also recognized immune cells by the acid they emit when they bind to antibodies, the group reports. Co-author and Yale bioengineer Tarek Fahmy adds, “There’s no other way to do this rapidly [with] high throughput. This is what we’re really excited about.”

The researchers carved their device from a high quality wafer of insulating material topped with a thin layer of silicon. They used standard techniques to build a stencil (shaped like the device they wanted), which they placed on the wafer. They then poured a solvent on top that etched away the exposed silicon.

Normally such a process would leave relatively thick wires, so to reduce the wires to nanosize they removed the stencil and let the etching continue. Reed says the combination of a good wafer and a slow-acting solvent gave them smoother, more precise nanowires than other groups have achieved by etching.

How long for a version you can hold in your hand? Reed will not speculate, but he says, “this is something I will see in my lifetime.”


Reverse Engineering Ourselves

Thursday, February 8th, 2007
scientific american

Scientific American publishes special editions of their magazine where they collect a bunch of essays around a common theme. These issues are standard reading for true geeks. Recently they published an issue called Secrets of the Senses. This was a collection of essays detailing the latest understanding science has on how all the human senses work. Essentially, it’s all about reverse engineering how the brain and nervous system work. You can probably guess where I’m going with this, that’s right, this info is all about how to build better robots.

An article of particular interest was Neuromorphic Microchips by Kwabena Boahen. He is working on leading edge research learning how to build microchips that mimic the eye’s nerve system. You can read an older article about his work here.

Bioengineering professor hopes to mimic the brain on a chip


Biblio Tech: RFID based Robotic Library at CSU

Thursday, February 8th, 2007

What can $38 million dollars get you, you ask? Well, Chicago State University has an answer to this question. A nearly fully autonomous, Radio Frequency Identification (RFID) based library using robotics! That’s right, when a student requests a book, CD, and/or DVD, the forklift-style robotic machine goes out into it’s 800,000+ volume collection, finds the appropriate category bin that the item is contained in, takes out the bin, and brings it to the front for check out. Then, the human librarian takes the book out of the bin, scans the RFID tag and checks out the book.

Robotic Librarians by the Numbers

* Top speed of CSU’s robotic librarians: 7 mph
* Average time for a robot to retrieve five books: 2.5 minutes
* Average time for a student to retrieve five books: 2 hours
* Capacity of CSU’s high-density storage: 800,000 volumes
* Robots making out in the stacks: 0

Wired Magazine Biblio Tech

Thanks Wired!