Show all abstracts
View Session
- Front Matter: Volume 7779
- Organic Semiconductors in Sensors and Bioelectronics I
- Organic Semiconductors in Sensors and Bioelectronics II
- Organic Semiconductors in Sensors and Bioelectronics III
- Organic Semiconductors in Sensors and Bioelectronics IV
- Organic Semiconductors in Sensors and Bioelectronics V
- Organic Semiconductors in Sensors and Bioelectronics VI
- Poster Session
Front Matter: Volume 7779
Front Matter: Volume 7779
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 7779, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
Organic Semiconductors in Sensors and Bioelectronics I
Optochemical sensor based on screenprinted fluorescent sensorspots surrounded by organic photodiodes for multianalyte detection
Show abstract
A compact, integrated photoluminescence based oxygen sensor, utilizing an organic light emitting device
(OLED) as the light source and an organic photodiode (OPD) as the detection unit, is described. The detection
system of the sensor array consists of an array of circular
screen-printed fluorescent sensor spots surrounded by
organic photodiodes as integrated fluorescence detectors. The OPD originates from the well-known Tang
photodiode, consisting of a stacked layer of copper phthalocyanine (CuPc, p-type material) and perylene
tetracarboxylic bisbenzimidazole (PTCBi, n-type material). An additional layer of tris-8-hydroxyquinolinatoaluminium
(Alq3, n-type material) was inserted between the PTCBi layer and cathode. An ORMOCERR layer
was used as encapsulation layer. For excitation an organic light emitting diode is used. The sensor spot and the
detector are processed on the same flexible substrate. This approach not only simplifies the detection system by
minimizing the numbers of required optical components - no optical filters have to be used for separating the
excitation light and the luminescent emission-, but also has a large potential for low-cost sensor applications.
The feasibility of the concept is demonstrated by an integrated oxygen sensor, indicating good performance.
Sensor schemes for other chemical parameters are proposed.
Organic Semiconductors in Sensors and Bioelectronics II
Large-area stretchable sensors with integrating organic CMOS ICs with Si-CMOS LSIs
Show abstract
We have successfully manufactured rubber-like large-area stretchable integrated circuits comprising printed elastic
conductors, organic transistor-based circuits, and silicon transistor-based circuits. Employing the first direct
integration of organic and silicon (Si) integrated circuits, we have realized to develop a stretchable electromagnetic
interference (EMI) measurement sheet that can detect EMI distribution on the surface of electronic devices by
wrapping the devices in the sheet. The stretchable devices can spread over arbitrary surfaces including free-formed
curvatures and movable parts, thereby significantly increasing the applications of electrical circuits.
Ink-jet printed colorimetric gas sensors on plastic foil
Show abstract
An all polymeric colorimetric gas sensor with its associated electronics for ammonia (NH3) detection targeting low-cost
and low-power applications is presented. The gas sensitive layer was inkjet printed on a plastic foil. The use of the foil
directly as optical waveguide simplified the fabrication, made the device more cost effective and compatible with large
scale fabrication techniques, such as roll to roll processes. Concentrations of 500 ppb of NH3 in nitrogen with 50% of RH
were measured with a power consumption of about 868 μW in an optical pulsed mode of operation. Such sensors foresee
applications in the field of wireless systems, for environmental and safety monitoring.
The fabrication of the planar sensor was based on low temperature processing. The waveguide was made of PEN or PET
foil and covered with an ammonia sensitive layer deposited by inkjet printing, which offered a proper and localized
deposition of the film. The influence of the substrate temperature and its surface pretreatment were investigated to
achieve the optimum deposition parameters for the printed fluid. To improve the light coupling from the light source
(LED) to the detectors (photodiodes), polymeric micro-mirrors were patterned in an epoxy resin.
With the printing of the colorimetric film and additive patterning of polymeric micro-mirrors on plastic foil, a major step
was achieved towards the implementation of full plastic selective gas sensors. The combination with printed OLED and
PPD would further lead to an integrated all polymeric optical transducer on plastic foil fully compatible with printed
electronics processes.
Organic Semiconductors in Sensors and Bioelectronics III
An organic semiconductor device for detecting ionizing radiation on a cellular level
Michael Bardash
Show abstract
Microdosimetry describes the energy deposition of ionizing radiation on a microscopic scale by quantifying
how Linear Energy Transfer (LET) of any radiation type creates local biological or physical damage sites. It
thus provides a model of damage on a molecular level (DNA). Microdosimetry characterizes cellular effects
and is used for understanding radiation oncology and human exposure. Ideal detectors for these applications
have the same physical size and radiation cross section as a (human) cell. That cross section is a strong
function of its composition, density, and the incident radiation's quality. Consequently, an organic, nano/micro
radiation sensor is highly desirable. Ideal materials for these devices have a high mobility, small carrier
trapping times, high resistivity, and unit density. Devices produced from these materials would be "tissue
equivalent." We present a solid state tissue equivalent detector using an organic semiconductor as the
active region. Many of the difficulties associated with ultrahigh resistance devices are eased by our novel
geometric approach. We present the design of a detector with an organic active region, effective solutions to
the materials problems, and device responses to radiation.
Organic Semiconductors in Sensors and Bioelectronics IV
Organic field-effect transistors applicable for gas and ion detection
Show abstract
Aside from other target applications, organic field-effect transistors (OFETs) are also promising devices for sensing
various kinds of analytes, including gases, ions and biomolecules. In this work ion-sensitive polymer-based OFETs will
be discussed. In detail, operational device instabilities caused by the movement of mobile ions in
poly(3-hexylthiophene)-based OFETs are investigated, when (a) an
ion-containing gate dielectric, polyvinyl alcohol (PVA), is
applied in a top-gate architecture and (b) ions are deliberately added to the organic semiconductor in a bottom-gate
architecture. The underlying mechanisms for the observed
source-to-drain channel current drifts upon bias stress are
thoroughly explained. In addition, device instabilities due to mobile ions within the dielectric are demonstrated with rigid
and flexible PVA-based OFETs including inkjet-printed source/drain electrodes and a meander-shaped top-gate
architecture, the latter enabling the realization of smart, integrated and low-cost OFET-based sensor systems.
Fabrication and characterization of carbon nanotube field-effect transistor biosensors
Matthew R. Leyden,
Canan Schuman,
Tal Sharf,
et al.
Show abstract
We report the fabrication of carbon nanotube field-effect transistors for biosensing applications and the development of
protocols for reliable protein and DNA sensing. The sensing method we employ is 'label free', relying only on the
intrinsic charge of the biological molecule of interest. We discuss fabrication issues that we have solved, for example the
preparation of clean surfaces, and the sensing protocol issues that we have encountered. Polylysine and ss-dna, highly
charged biological molecules, are used as model systems to illustrate the performance of our biosensors.
Organic Semiconductors in Sensors and Bioelectronics V
Luminescent conjugated oligothiophenes: optical dyes for revealing pathological hallmarks of protein misfolding diseases
Show abstract
Luminescent conjugated polymers (LCPs) have been frequently utilized for optical biosensors. The detection schemes of
these sensors are employing the light harvesting properties or the conformation sensitive optical properties of the
conjugated polymers. LCPs have been utilized as colorimetric and fluorescent sensing elements for the recording of
biological processes. However, LCPs have several limitations for being used as real time in vivo imaging agents. In this
regard, novel thiophene based molecular scaffolds, denoted luminescent conjugated oligothiophenes (LCOs) have been
developed. These LCOs are chemically defined molecules having distinct side chain functionalizations and a precise
number of thiophene units. Herein the utilization of LCOs as specific ligands for the pathological hallmarks underlying
protein misfolding diseases, such as Alzheimer's disease, is described. The use of the conformation sensitive optical
properties of the LCOs for spectral separation of these pathological entities in a diversity of in vitro, ex vivo or in vivo
systems is demonstrated. The protein aggregates are easily identified due to the conformation-dependent emission profile
from the LCOs and spectral assignment of protein aggregates can be obtained. Overall, these probes will offer practical
research tools for studying protein misfolding diseases and facilitate the study of the molecular mechanism underlying
these disorders.
Organic Semiconductors in Sensors and Bioelectronics VI
Performance and parameter variation of flexible organic thin film transistors in multicomponent organic sensors
Show abstract
Here we report on the fabrication and detailed characterization of flexible low-voltage organic thin-film transistors
directly integrated with pyro- and piezoelectric sensors. The functional layer of the capacitive sensors is a ferroelectric
fluoropolymer. The transistors on the other hand are based on a high-k nanocomposite gate dielectric and on pentacene
as the organic semiconductor and can be operated well below 5V. It is shown, that the transistors can be fabricated on the
fluororpolymer layer. Since the control of parameter spread is a very important topic in large area electronics, it was
attempted to investigate the homogeneity of a significant set of devices by individual assessment of the layer
composition and thickness, the pentacene morphology, the actual geometry and the electrical parameters. It turned out
that starting from the measured device parameters such as layer thickness, capacitance, channel dimension, grain size
and threshold voltage, the drain current can be calculated with high accuracy in a specified operation point. In addition, it
is shown that the main influence on the parameter spread originates from the variations in the threshold voltage. Storage
in air destroys the transistors on the long term, whereas bias stress measurements under inert conditions reveal that the
interfaces are very stable.
Advances toward commercialization of a new generation of low cost (O)LED-based dissolved oxygen and bioanalyte monitors
Show abstract
Recent advances toward commercialization of a new generation of
low-cost LED- and OLED-based monitors for
dissolved oxygen (DO), and multiple (bio)analytes such as glucose, lactate, alcohol, and cholesterol are described.
The design of the DO monitors, which contain no optical fibers, filters, mirrors, or lens, is significantly simpler and
consequently lower-cost than that of commercial LED-based DO monitors. The multiple (bio)analyte monitors are
based on a DO monitor and the oxidase enzyme specific to each analyte. The potential advantages and
disadvantages of the OLED- vs LED-based monitors is also discussed.
Poster Session
A green-absorbing dendrimer-based photodetector for image sensing applications
Show abstract
The synthesis and photosensing ability of a novel green-absorbing dendrimer are presented. The photoresponse of a
photodiode comprising a bulk heterojunction blend of a first generation ketocyanine-cored dendrimer with carbazole
dendrons and fluorenyl surface groups and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) shows good spectral
selectivity for digital camera applications. The narrow absorbing photodiode achieved an external quantum efficiency of
2.9% at 515 nm and maintained a profile similar to the absorption of the unblended dendrimer.