Manufacturing Bits: May 8

Electrolyte transistors
Delft University of Technology, the Centre National de la Recherche Scientifique (CNRS) and NTT have developed a nanotransistor technology that will make it easier to measure the concentration of different electrolytes in the body.

Electrolytes involve nutrients and chemicals in the body. They perform important functions and a disruption of the electrolyte balance is often dangerous. But testing for electrolyte imbalances is challenging, as a number of tests must be performed.

In response, researchers from Delft and others have devised a ‘0D’ ion-selective field-effect transistor (ISFET) as well as a sensor. Measuring just 25nm, the new device is smaller than conventional nanowire ISFETs.

A ‘0D’ ion-selective field-effect transistor (ISFET) Source: Delft University of Technology

In a diagnostic tool, the 0D-ISFET enables cheaper and easier bedside testing compared to conventional methods. The technology requires only a tiny amount of blood for testing. Compared to current devices, the 0D-ISFET showed a higher sensitivity to the presence of electrolytes. It is possible to sense electrolytes in small concentrations.

The technology is still in R&D. But one day, it could help patients who undergo regular ionogram measurements or for those who take antidiabetic, corticoid or lithium medications.

DNA detection
In what could help gain insight into diseases, Imec has developed a new technology that could help unravel the mysteries of DNA.

Imec has found a way to enable direct identification of single DNA bases. The R&D organization has combined nanopore sensing and single-molecule surface enhanced Raman spectroscopy (SERS) for single-molecule identification.

In the human body, chromosomes are divided into 30,000 smaller regions called genes. Each gene consists of a string of nucleotide bases, dubbed A, C, G and T. In total, human DNA has 3 billion bases. The exact order of these bases is known as the DNA sequence. DNA is a molecule that carries the genetic instructions in living things. A complete set of DNA is called the genome.

DNA sequencing is a technique that determines the order of DNA bases, which is important for the study of genetics, gene mutations and therapies. But DNA sequencing techniques often use fluorescent labeling, which is costly and time-consuming, according to Imec.

Imec has developed an alternative approach. Using optical spectroscopy, the technique makes use of nanofluidics to drive the DNA strand through an engineered plasmonic nanoslit. Then, SERS makes a “fingerprint” of the adsorbed nucleobases up to the level of molecular bonds.

The spectroscopic signal is enhanced both by a gold coating on top of the nanoslit, and the shape of the nanoslit. “The result reported here is an important step towards a solution for fast and direct sequencing up to the epigenetic level,” said Chang Chen, senior researcher at Imec.

Sub-10nm nanoslit captures DNA Source: Imec

VLSI preview
The 2018 Symposia on VLSI Technology & Circuits is taking place in Honolulu, Hawaii from June 19-21. At the event, there are a number of papers.

At the event, Intel will present a paper on a spiking neural network device in a 10nm finFET process. The device combines sparse connectivity, stochastic operation, voltage scaling and power gating. Energy efficiency can be as low as 3.8pJ per synaptic operation (SOP) at 2.6GSOP/s, according to the abstract.

Also at the event, GlobalFoundries will present results on laser-induced grain growth within copper interconnects. Researchers will demonstrate a 30% reduction in line resistance. It delivers a 15% improvement in RC and improvement in IDsat of 2-5%.

MIT will discuss a CMOS-based molecular clock. As an alternative to traditional atomic clocks, MIT is proposing to use the 231.061GHz spectral line of carbonyl sulfide, enabling the first chip-scale molecular clock. In addition, MIT will talk about Navion, an integrated odometry accelerator for use in autonomous miniaturized robots.

“The chip uses inertial measurements and mono-stereo images to estimate a drone’s trajectory, as well as to generate a 3D map of the environment. The on-chip integration reduces energy and footprint, and it eliminates costly off-chip processing and storage. Fabricated in 65nm CMOS, it can process 752 x 480 stereo images at up to 171fps and inertial measurements at up to 52kHz. Further, the chip is configurable to maximize accuracy, throughput, and energy-efficiency across various environmental conditions,” according to the abstract.