| 1. |
- Andersson, Henrik, et al.
(author)
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Inkjet printed silver nanoparticle humidity sensor with memory effect on paper
- 2012
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In: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:6, s. 1901-1905
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Journal article (other academic/artistic)abstract
- In this paper, the design and the manufacture of an inkjet printed resistive type humidity sensor on paper are reported. After having been exposed to humidity above a given threshold level, the resistance of the sensor decreases substantially and remains at that level even when thehumidity is reduced. It is possible to deduce the humidity level by monitoring the resistance. The main benefit of the printed sensor presented in this case is in relation to its very low production costs. It has also been shown that both the ink type and this paper combination used prove to be crucial in order to obtain the desired sensor effect. More research is required in order to fully understand the humidity sintering effect on the nano particle ink and the role of the substrate. However, the observed effect can be put to use in printed humidity sensors which possess a memoryfunction. The sensor can be used in various applications for environmental monitoring, for example, in situations where a large number of inexpensive and disposable humidity sensors are required which are able to detect whether they have been subjected to high humidity. This could be the checking of transportation conditions of goods or monitoring humidity within buildings. © 2001-2012 IEEE.
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| 2. |
- Andersson, Henrik, et al.
(author)
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Investigation of Humidity Sensor Effect in Silver Nanoparticle Ink Sensors Printed on Paper
- 2014
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In: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 14:3, s. Art. no. 6615915-
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Journal article (peer-reviewed)abstract
- Thin inkjet-printed tracks of silver nanoparticles have previously been observed to show a non-reversible decrease in resistance when exposed to a high degree of relative humidity and thus providing sensor functionality with a memory effect. This paper provides a more in-depth explanation of the observed humidity sensor effect that originates from inkjet-printed silver nanoparticle sensors on a paper substrate. It is shown that the geometry of the sensor has a large effect on the sensor's initial resistance, and therefore also on the sensor's resistive dynamic range. The importance of the sensor geometry is believed to be due to the amount of solvent from the ink interacting with the coating of the paper substrate, which in turn enables the diffusion of salts from the paper coating into the ink and thus affecting the silver ink.
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| 3. |
- Li, Jiantong, et al.
(author)
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Ink-jet printed thin-film transistors with carbon nanotube channels shaped in long strips
- 2011
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In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 109:8, s. 084915-
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Journal article (peer-reviewed)abstract
- The present work reports on the development of a class of sophisticated thin-film transistors (TFTs) based on ink-jet printing of pristine single-walled carbon nanotubes (SWCNTs) for the channel formation. The transistors are manufactured on oxidized silicon wafers and flexible plastic substrates at ambient conditions. For this purpose, ink-jet printing techniques are developed with the aim of high-throughput production of SWCNT thin-film channels shaped in long strips. Stable SWCNT inks with proper fluidic characteristics are formulated by polymer addition. The present work unveils, through Monte Carlo simulations and in light of heterogeneous percolation, the underlying physics of the superiority of long-strip channels for SWCNT TFTs. It further predicts the compatibility of such a channel structure with ink-jet printing, taking into account the minimum dimensions achievable by commercially available printers. The printed devices exhibit improved electrical performance and scalability as compared to previously reported ink-jet printed SWCNT TFTs. The present work demonstrates that ink-jet printed SWCNT TFTs of long-strip channels are promising building blocks for flexible electronics.
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| 4. |
- Nilsson, Hans-Erik, et al.
(author)
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Characterization of moisture sensor based on printed Carbon-Zinc energy cell
- 2005
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In: Polytronic 2005: 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics - Proceedings. - Piscataway, NJ : IEEE conference proceedings. - 0780395530 ; , s. 82-85
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Conference paper (peer-reviewed)abstract
- In this work we present a simple printed moisture sensor fabricated using electronic inks on a multilayer paper structure. The sensor is based on a Carbon-Zinc type energy cell and provides power to a readout electronic circuit when activated by moisture. The sensors are based on a number of our filed patents according to which the sensor is used for both event detection and as a power source for the processing electronics. Typical applications are moisture and leakage detection in buildings, water pipe lines, smart packages and health care systems such as smart incontinence sensors. As the detector is triggered, it powers up an electronic circuit (polymer based or silicon based) that starts communication with the alarm server. In the simplest systems a sound or a light alarm is started to alert the user. In this work we present a characterization of some critical parameters of the sensor such as power driving capability, linearity, internal memory effects and saturation. In addition, we examine a specific application, when sensor is used as defrosting alarm for surveillance of frozen articles during transport.
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| 5. |
- Nilsson, Hans-Erik, et al.
(author)
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Printed write once and read many sensor memories in smart packaging applications
- 2011
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In: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 11:9, s. 1759-1767
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Journal article (peer-reviewed)abstract
- A horizontal printed Write Once Read Many (WORM) resistive memory has been developed for use in wireless sensortags targeting single event detection in smart packaging applications. The WORM memory can be programmed using a 1.5 V printedbattery. An alternative programming method is to use chemical sintering which allows the development of exposure-time triggeredsingle event tags that can be accessed wirelessly. The new WORM memory has very low losses in the ON-state which allows directintegration into antenna structures.A sensor tag that utilizes the WORM memory functionality and the well established Electronic Article Surveillance (EAS)communication standard has been outlined. Both active and fully passive sensor tag solutions have been proposed.The role of printed electronics in smart packaging applications has been reviewed and discussed. Important enabling factors forthe future development have been highlighted, such as the need for hierarchical design and test tools, better printed interconnecttechnologies as well as better components that allow communication with existing information and communication technology (ICT)standards. This is illustrated and underlined by the presented smart packaging concept demonstrators.
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| 6. |
- Nilsson, Hans-Erik, et al.
(author)
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System integration of electronic functions in smart packaging applications
- 2012
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In: IEEE Transactions on Components, Packaging and Manufacturing Technology. - 2156-3950. ; 2:10, s. 1723-1734
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Journal article (peer-reviewed)abstract
- A system integration scheme relevant for smart packaging applications is presented. Recent advances in printed electronics, radio frequency identification tag production, and standardization of communication protocols are factors that increase the design freedom for new applications. As in all new technology fields, the first products are expected to appear in the high-cost segment attracting early adopters in the form of niche products. A reasonable assumption is that these products will come from hybridization of different types of technologies. Such a scenario is likely since no technology solution available can provide all features that these types of applications demand. There is a need of standard solutions for hybridization of silicon devices and printed (or foil-type) components. Conductive ink technology is a powerful tool for hybridization and customization of large-area electronics, providing 3-D integration and large-area customization. However, high-performance communication and advanced processing demand the use of silicon. Smart hybridization solutions allow combination of the best from both worlds. This paper analyzes the requirements on hybridization technologies suitable for smart packaging applications and provides design examples on integration of intrusion surveillance solutions for cellulose-based packaging applications. It shows that even though the current hybridization technologies are far from optimal, they can provide a considerable design freedom and system performance. © 2011-2012 IEEE.
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| 7. |
- Sidén, Johan, et al.
(author)
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Electric and Electromagnetic Coupled Sensor Components for Passive RFID
- 2011
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In: 2011 IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems, COMCAS 2011. - : IEEE conference proceedings. - 9781457716928 ; , s. 1-5
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Conference paper (peer-reviewed)abstract
- This work discuss the possibilities of integrating passive sensor components to passive UHF RFID tags. The sensor system works by degrading a tag's communication performance in proportion to a sensed quantity. Two approaches are studied, sensors directly integrated to tag antenna structures and sensors electromagnetically coupled to tag antennas. The em coupled sensors provide the possibility to produce small sensor components as easily applied add-ons to ordinary commercial RFID tags.
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| 8. |
- Sidén, Johan, et al.
(author)
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Remote Moisture Sensing utilizing Ordinary RFID Tags
- 2007
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In: Proceedings of IEEE Sensors. - New York : IEEE conference proceedings. - 9781424412617 ; , s. 308-311
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Conference paper (peer-reviewed)abstract
- The paper presents a concept where pairs of ordinary RFID tags are exploited for use as remotely read moisture sensors. The pair of tags is incorporated into one label where one of the tags is embedded in a moisture absorbent material and the other is left open. In a humid environment the moisture concentration is higher in the absorbent material than the surrounding environment which causes degradation to the embedded tag’s antenna in terms of dielectric losses and change of input impedance. The level of relative humidity or the amount of water in the absorbent material is determined for a passive RFID system by comparing the difference in RFID reader output power required to power up respectively the open and embedded tag. It is similarly shown how the backscattered signal strength of a semi-active RFID system is proportional to the relative humidity and amount of water in the absorbent material. Typical applications include moisture detection in buildings, especially from leaking water pipe connections hidden beyond walls. Presented solution has a cost comparable to ordinary RFID tags, and the passive system also has infinite life time since no internal power supply is needed. The concept is characterized for two commercial RFID systems, one passive operating at 868 MHz and one semi-active operating at 2.45 GHz.
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| 9. |
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| 10. |
- Unander, Tomas
(author)
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Characterization of Low Cost Printed Sensors for Smart Packaging
- 2008
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Licentiate thesis (other academic/artistic)abstract
- Currently there are very significant interests in printed electronics in the world. The possibility to produce electronics in a roll to roll printing process will considerably reduce the cost of the electronic devices. However, these new devices will most probably not replace the traditional silicon based electronics, but will be a complement in low cost applications such as in intelligent packages and other printable media. One interesting area is printable low cost sensors that add value to packages. In this thesis a study of the performance of low cost sensors is presented. The sensors were fabricated using commercial printing processes used in the graphical printing business. The sensors were characterized and evaluated for the intended application. The evaluated sensors were moisture sensing sensor solutions and touch sensitive sensor solutions. A printable touch sensitive sensor solution is presented where the sensor is incorporated into a high quality image such as in point of sales displays. The sensor solution showed good touch sensitivity at a variety of humidity levels. Four printed moisture sensor concepts are presented and characterized. Firstly, a moisture sensor that shows good correlation to the moisture content of cellulose based substrates. Secondly, a sensor that measures the relative humidity in the air, the sensor has a measuring accuracy of 0.22% at high relative humidity levels. Thirdly, a moisture sensor that utilizes unsintered silver nano-particles to measure the relative humidity in the air, the sensor has a linear response at very low relative humidity levels. And fourth, an action activated energy cell that provides power when activated by moisture. A concept of remote moisture sensing that utilizes ordinary low cost RFID tags has also been presented and characterized. The remote sensor solution works both with passive and semi-passive RFID systems. The study shows that it is possible to manufacture low cost sensors in commercial printing processes.
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