Manufacturing Bits: June 10

Hyperspectral imaging cameras; organic solar; EEG headsets.

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At the recent ITF Brussels 2014 event in Belgium, Imec and its partners described a plethora of new technologies in several arenas. Here’s just a small sample of what Imec and others are working on:

Hyperspectral imaging cameras
Imec and Ximea have devised the world’s smallest hyperspectral imaging camera. Hyperspectral cameras divide the light spectrum into many small wavelength bands. They capture the spectral fingerprint of an object and show detailed information.

The technology involves integrating Imec’s hyperspectral imaging sensors together with Ximea’s xiQ USB3.0 camera product line. The imager product available from Imec scans 100 spectral bands in the 600nm to 1000nm wavelength region. The technology is integrated into Ximea’s xiQ camera product line. The system measures 26.4- x 26.4- x 21.6-mm and weighs 27 grams, making it world’s smallest industrial USB3 Vision and hyperspectral imaging camera. XiQ cameras consume only 1.8 W.

The world's smallest USB 3.0 camera (Source: Ximea

The world’s smallest USB 3.0 camera (Source: Ximea

Three types of standard spectral image sensor designs are available: 100 bands linescan design; 32 bands snapshot tiled design; and a new snapshot mosaic designs featuring 16 bands in a matrix of 4×4 per-pixel filters. A USB3.0 interface includes a power supply over USB technology. This removes the need for expensive and bulky frame-grabbers and separate power supplies.

“Hyperspectral imaging is not new in the world of high-end remote sensing instruments such as satellites and airborne systems. (Imec and Ximea) will bring this technology into the hands of the numerous drone and UAVs companies that want to fly compact multispectral/hyperspectral imaging cameras to serve the emerging precision farming industry,” added Jerome Baron, Business development manager of Imec’s imaging activities.

Organic solar
A new EU-funded research project aims to speed up the development of organic photovoltaic (OPV) cells. Comprising of ten European universities, companies and organizations, the MUJULIMA project is targeting cost-efficient OPV cells that enable module efficiencies above 15% and lifetimes of over 10 years.

The consortium members include Holst Centre/TNO, Imec, ECN, Eindhoven University of Technology, University of Wuppertal, CEA-LITEN, PCAS, DisaSolar and NEN.

OPVs make use of thin-film photovoltaic technology. The technology features flexible substrates and a tunable absorption window. Although the power conversion efficiency of organic solar cells has increased in the last decade, further enhancements are needed to make the production of OPV more scalable.

Imec’s fullerene-free OPV cell concept was used to process an OPV module with a conversion efficiency of 5.3%. (Source: Imec)

Imec’s fullerene-free OPV cell concept was used to process an OPV module with a conversion efficiency of 5.3%. (Source: Imec)

The EU-based program has three key objectives. First, the group hopes to devise photoactive and interlayer materials for creating multi-junction OPVs. Second, it will develop up- and down-converter materials. And finally, it hopes to improve the outdoor performance of existing encapsulation methods.

In one breakthrough, Imec recently rolled out fullerene-free OPV multilayer stacks, which achieved a record conversion efficiency of 8.4%. “Fullerenes are the dominant acceptor materials in current OPV cells due to their ability to accept stable electrons and their high electron mobility,” according to Imec. “However, the small absorption overlap with the solar spectrum limits the photocurrent generation in fullerene acceptors, and their deep energy level for electron conduction limits the open-circuit voltage. Imec implemented two fullerene-free materials as acceptor, increasing open-circuit voltages compared to OPV cells with fullerene acceptors.”

To increase the efficiency of organic solar cells, complex tandem architectures are often proposed to combine the exciton harvesting of multiple photo-active materials. Imec proposed a simple three-layer stack to improve the spectral range.

This results in a quantum efficiency above 75% between 400nm and 720nm. With an open-circuit voltage close to 1V, a power conversion efficiency of 8.4 percent is achieved. These results confirm that multilayer cascade structures are a promising alternative to conventional donor-fullerene organic solar cells.

EEG headsets
NeuroPro has devised a novel electroencephalogram (EEG) headset. The headset, dubbed NeuroTrail, is a wireless headset for use in the real-time capture of EEG signals as well as other biometric data.

EEG measures electrical activity on the scalp from the firing of neurons. It is conducted in real time and is one of the least invasive methods. EEG reveals several conditions, namely epilepsy. Epilepsy is a chronic brain disorder characterized by recurrent seizures.

Developed in partnership with Imec and Creaholic, the headset integrates Imec and Holst Centre’s body area networks (BANs). The headset designed by Creaholic achieves high-quality EEG recordings with very low setup time.

NeuroTrail acommodates 1-8 measurement channels and individual electrodes can be easily relocated on standardized positions of the international 10-20 system. The system also consists of wireless connectivity to a smart phone or tablet.

Integrated with NeuroPro’s visualization software, the headset will enable brain signal analysis by leveraging the latest developments in mobile computing and cloud computing technology. “We have been creating circuits and compact systems for wearable EEG for the past six years,” said Chris van Hoof, program director for wearable healthcare at imec/Holst Centre. “But achieving clinical-grade functionality in a consumer-grade headset required rethinking the electronic subsystem to make Imec technology fit inside.”

In a separate but related announcement, Holst Centre and Imec have unveiled a prototype flexible health patch weighing just 10 grams. The patch uses real-time electrocardiogram (ECG), tissue-contact impedance and accelerometer information to accurately monitor physical activity. Thanks to advanced system in package (SiP) technology from Shinko, the electronics module measures less than two by two centimeters.