Infotech Oulu Annual Report 2016 - New Generation Optoelectronics for Measurement Applications (NEGOMA)

Emeritus Professor Risto Myllylä, Senior Research Fellow Matti Kinnunen and Professor Tapio Fabritius, Optoelectronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu
risto.myllyla(at)oulu.fi, matti.kinnunen(at)oulu.fi, tapio.fabritius(at)oulu.fi
http://www.infotech.oulu.fi/negoma

Background and Mission

NeGOMA group focuses on development of solution processable components and systems (sensors and sensor networks, light sources, light detectors, optical components etc) for different kinds of measurement applications. The motivation is to find new ways of applying the new generation optoelectronics to generate high level scientific knowledge but also find solutions which have a real commercial potential in industry and health care. In addition, NeGOMA group members investigate and develop different measurement methods for various applications. NeGOMA group is an active member in PrintoCent as well as a member in More-than-Moore (MtM) RAE consortium. MtM succeeded well in the evaluation, getting 6/6 points in the Vidi category.

Scientific Progress

Printable Autonomously Working Activity Sensor with Wireless Data Transmission

An autonomous wireless activity sensor system, based on printed elements, was successively demonstrated. The impact of kinetic energy is transferred to an electrical signal by a piezo element and then wirelessly transmitted by silk screen printed planar antennas. In order to make the sensing system capable to stand for harsh measurement environments, all the fragile silicon based electronics was eliminated and the design was kept as simple as possible. Since the printed electric components are usually flexible and really thin, they are well suited for this type of environments.

The functional performance of the developed system was tested by measuring the impact of weight to the piezo by placing a plastic tube on top of the element. A weight of 87 g was then dropped into the tube from a height of 380 mm. The weight bounced few times on the piezo and the signal caused by these impacts was send to an antenna, which was connected to the piezo element (which can be printed as well). Another similar antenna was aligned with the first one for the best coupling, and was then connected to an oscilloscope which measured the wirelessly transmitted signal. All of the measurements were photographed with a high speed camera to determine the height of each bounce. The height measurement resolution was 1 mm. The first four bounces were taken into an account to analyze the performance of the system.

The background noise of the received signal was high at first, and several options for its attenuation were investigated. The best option was found to be a Faraday cage, which was then built around the antennas. This blocks the electromagnetic radiation from the surrounding environment.

Fig. 1 shows the voltage as a function of the drop height for each measurement. The vertical lines mark the four drop heights, which varies some amount due to the imperfect drop of the weight. When considering only the first (380 mm height) and the last (50 mm height) drops, the signal level can be clearly separated. Hence, it is demonstrated that with this very simple design two impacts with different forces can be wirelessly transmitted and separated from each other.

Although the used piezo was not printed one in this demonstration, there is lot of research ongoing around that subject and it will result to a fully printable activity sensing system in the future.  That is expected to widen the possible application fields for the developed technology.

 

Figure 1. Plot of 17 measurements for the weight with four first bounces. The larger the kinetic energy (height of weight), the higher the received voltage.

 

Gold Nanoparticles for Surface-enhanced Vibrational Spectroscopy

Beneficial properties of gold nanostars (NSts) as signal enhancers for tissue and cell imaging were demonstrated for surface-enhanced vibration spectroscopy (SEVS), including surface-enhanced Raman scattering (SERS), and surface-enhanced infrared absorption spectroscopy (SEIRAS) with an attenuated total reflectance (ATR) and infrared reflection-absorption spectroscopy (IRRAS) configurations.

 


Figure 2. (a) SEM images of a patterned Si chip comprising regions with a 5 nm gold layer, the PEG polymer attached on top, and immobilized NSts; (b) SEM image of a patterned Si chip comprising regions with a 5 nm gold layer and PEG without immobilized NSts.

 

NSts were used in SEVS scenarios in plasmonic chip-based systems containing self-assembled NSts on a Si waveguides either by evaporation or subsequent immobilization mediated by a gold layer and dimercapto polyethylene glycol (PEG) (Figure 2). Both obtained plasmonic systems are able to significantly enhance Raman and mid-infrared signals. SERS and SEIRAS properties of such substrates were demonstrated. The IR absorbance of analyte molecules placed on NSt-film deposited on a Si ATR crystal was up to 10 times higher for thioglycolic acid (TGA) and 2 times higher for bovine serum (BSA) albumin compared to a bare Si waveguide. Efficiencies of NSts and spherical citrate-capped (c-NPs) and “bare” laser-synthesized gold nanoparticles (la-NPs) were compared as SEIRAS substrates for the detection of TGA and BSA. The signal obtained from AuNSts was at least 2 times higher for TGA molecules in comparison with spherical gold nanoparticles, which was explained by a more efficient generation of hot spots on anisotropic surface of NSts, leading to a high electric field strength surrounding the particles (Figure 3).

Figure 3. Band height at 1709 cm−1 of evaporated TGA solution and TGA mixed with laser-synthesized nanoparticles (la-NPs), citrate-capped nanoparticles (c-NPs) and NSts.

NeGOMA group people participated in several conferences and presented their results during year 2016. These conferences include international and national conferences, for example: The International Conference “BiOS” in frames of SPIE Photonics West (San-Francisco, USA). In frames of BiOS, Ms. Bibikova was awarded Prizmatix young investigator award.

 

Personnel

professors

2

senior research fellows

3

postdoctoral researchers

7

doctoral students

11

other research staff

2

total

25

person years for research

22

 

Doctoral Theses

Augustine, B (2016) Efficiency and stability studies for organic bulk heterojunction solar cells. Acta Universitatis Ouluensis, Technica C 596.

Aikio, S (2016) Improving robustness and disposability of integrated Young interferometer sensors for portable diagnostics. VTT Science 101.

Happonen, T (2016) Reliability studies on printed conductors on flexible substrates under cyclic bending. Acta Universitatis Ouluensis, Technica C 571.

Selected Publications

[1] P. Vilmi, M. Nelo, J.-V. Voutilainen, J. Palosaari, J. Pörhönen, S. Tuukkanen, H. Jantunen, J. Juuti and T. Fabritius, “Fully printed memristors for a self-sustainable recorder of mechannical energy”, Flexible and Printed Electronics, 1(2) (2016).

[2] O. Bibikova, J. Haas, A. I. Lopez-Lorente, A. Popov, M. Kinnunen, I. Meglinski, B. Mizaikoff, “Towards enhanced optical sensor performance: SEIRA and SERS with plasmonic nanostars,” Analyst, DOI 10.1039/C6AN02596J (2017).

[3] O. Bibikova, P. Singh, A. Popov, G. Akchurin, A. Skaptsov, I. Skovorodkin, V. Khanadeev, D. Mikhalevich, M. Kinnunen, G. Akchurin, V. Bogatyrev, N. Khlebtsov, S. Vainio, I. Meglinski, and V. Tuchin, “Shape-dependent interaction of gold nanoparticles with cultured cells at laser exposure,” Laser Physics Letters, 14, 055901 (2017).

[4] S. Uusitalo, M. Kögler, A.-L. Välimaa, A. Popov, Yu. Ryabchikov, V. Kontturi, S. Siitonen, J. Petäjä, T. Virtanen, R. Laitinen, M. Kinnunen, I. Meglinski, A. Kabashin, A. Bunker, T. Viitala and J. Hiltunen, “Detection of Listeria innocua on disposable SERS substrates with gold nanoparticles,” RSC Advances, 6(67), 62981-62989 (2016).

[5] S. Uusitalo, M. Kögler, A.-L. Välimaa, J. Petäjä, V. Kontturi, S. Siitonen, R. Laitinen, M. Kinnunen, T. Viitala, and J. Hiltunen, "Stability optimization of microbial surface-enhanced Raman spectroscopy detection with immunomagnetic separation beads," Opt. Eng. 56(3), 037102 (2017).

Last updated: 12.4.2017