Manufacturing Bits: Nov. 5

Nano Bulletproof Suit
Luxury tailoring house Garrison Bespoke has developed a bulletproof suit based on carbon nanotubes.

The Garrison Bespoke bulletproof suit is made with carbon nanotubes, which were originally developed to protect the U.S. 19th Special Forces in Iraq. The patented material is thinner and 50% lighter than Kevlar, which is traditionally used for bulletproof gear.

The suit also protects against stabbing. The carbon nanotubes harden on impact, preventing a knife from penetrating. This week, the company will demo the suit in action. It will have a live ammo field-testing event at the Ajax Rod and Gun Club in Ontario, Canada. The cost of a Garrison Bespoke bulletproof suit starts at $20,000.

“After receiving requests from high-profile clients who travel to dangerous places for work, we set out to develop a lightweight, fashion-forward bulletproof suit as a more discreet and stylish alternative to wearing a bulky vest underneath,” said Michael Nguyen, co-owner and Bespoke tailor of Garrison Bespoke, in a statement. Garrison Bespoke is a luxury menswear boutique in Toronto.

Implantable Nanotubes
Single-walled carbon nanotubes are ideal for biomedical applications. Carbon nanotubes exhibit a fluorescent signal with little interference in a system.

The Massachusetts Institute of Technology (MIT) has devised an implantable sensor based on carbon nanotubes. The sensor, which is implanted under the skin, can detect nitric oxide, according to MIT. Nitric oxide is a cellular signaling molecule, which is involved in various physiological processes.

“Nitric oxide has contradictory roles in cancer progression, and we need new tools in order to better understand it,” said Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT, on the university’s Web site. “Our work provides a new tool for measuring this important molecule, and potentially others, in the body itself and in real time.”
Researchers created two different types of sensors. The first one can be injected into the bloodstream. The other sensor consists of nanotubes embedded in a gel made from alginate, which is a polymer found in algae. The polyethylene glycol ligated copolymer stabilizes the single-walled carbon nanotube sensors in a solution.

Researchers demonstrated that alginate-encapsulated single-walled carbon nanotubes can function as implantable inflammation sensors for nitric oxide detection, with no intrinsic immune reactivity or other adverse response for more than 400 days.

Synaptic Transistors
Harvard School of Engineering and Applied Sciences (SEAS) has devised a transistor that mimics a synapse. In the nervous system, a synapse permits a neuron to pass an electrical signal to another cell. Harvard’s synaptic transistor modulates the flow of information and adapts to changing signals.

This neuromorphic device paves the way for new computing paradigms to explore cognition. The synaptic transistor consists of samarium nickelate (SmNiO3) material. The transistor is sandwiched between two platinum electrodes. And the device is adjacent to an ionic liquid. All told, the transistor is a correlated electron system with an insulator–metal transition temperature at 130°C in bulk form.

When a voltage is applied to the device, ions move in and out of the crystal lattice of the SmNiO3 device. This, in turn, becomes a synapse channel between two platinum terminals.

The resistance modulation can be controlled by the film microstructure. The system can simulate the time difference between post-neuron and pre-neuron spikes. As a result, synaptic spike-timing dependent plasticity learning behavior is realized, according to researchers.

“The transistor we’ve demonstrated is really an analog to the synapse in our brains,” said Jian Shi, a postdoctoral fellow, on Harvard’s Web site. “Each time a neuron initiates an action and another neuron reacts, the synapse between them increases the strength of its connection. And the faster the neurons spike each time, the stronger the synaptic connection. Essentially, it memorizes the action between the neurons.”

The synaptic transistor offers several advantages over traditional silicon-based chips. “This system changes its conductance in an analog way, continuously, as the composition of the material changes,” Shi said. “It would be rather challenging to use CMOS, the traditional circuit technology, to imitate a synapse, because real biological synapses have a practically unlimited number of possible states—not just ‘on’ or ‘off.’”