Abstract: We report on a micro-dispensing system for 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) to enable homogenous crystallization and uniform filmmorphology of the dispensed droplets using a two-solvent mixture along with the use of aninsulating binder. This solution composition results in a controlled evaporation of the dropletin ambient air such that the Marangoni flow counteracts the outward convective flow toenable uniform radial crystal growth from the edge towards the center of the drops.The consequence of this process is the high degree of uniformity in the crystallization of thedrops, which results in a reduction in the performance spread of the organic field effecttransistors (OFET) created using this process. The addition of the insulating binder furtherimproves the reduction in the spread of the results as a trade-off to the reduction in mobilityof the transistors. The transfer curves of the OFETs show a tight grouping due to thecontrolled self-alignment of the TIPS-pentacene crystals; this repeatability was furtherhighlighted by fabricating p-type inverters with driver to load ratios of 8:1, wherein theoutput inverter curves were also grouped tightly while exhibiting a gain of greater than 4 inthe switching region. Therefore, the reliability and repeatability of this process justifies itsuse to enable large area solution-processed printed circuits at the cost of reduced mobility.
Abstract: With the globalization of the integrated circuit (IC) design flow of chip fabrication, intellectual property (IP) piracy is becoming the main security threat. While most of the protection methods are dedicated for digital circuits, we are trying to protect radio-frequency (RF) designs. For the first time, we applied the split manufacturing method in RF circuit protection. Three different implementation cases are introduced for security and design overhead tradeoffs, i.e., the removal of the top metal layer, the removal of the top two metal layers and the design obfuscation dedicated to RF circuits. We also developed a quantitative security evaluation method to measure the protection level of RF designs under split manufacturing. Finally, a simple Class AB power amplifier and a more sophisticated Class E power amplifier are used for the demonstration through which we prove that: (1) the removal of top metal layer or the top two metal layers can provide high-level protection for RF circuits with a lower request to domestic foundries; (2) the design obfuscation method provides the highest level of circuit protection, though at the cost of design overhead; and (3) split manufacturing may be more suitable for RF designs than for digital circuits, and it can effectively reduce IP piracy in untrusted off-shore foundries.
Abstract: Communications between vehicles are seen as a solution for road transport problems, such as accidents, inefficiencies, traffic congestions, fuel consumption, and exhaust emissions. However, before implementing such a solution, some preliminary analysis is needed. First, the most convenient communications technologies should be selected for each application and specific communications architecture should be deployed to support such services. Standardization is essential for successful deployment.[...]
Abstract: An availability and a reliability prediction has been made for a high-voltage direct-current (HVDC) module of VSC (Voltage Source Converter) containing DC/DC converter, gate driver, capacitor and insulated gate bipolar transistors (IGBT). This prediction was made using published failure rates for the electronic equipment. The purpose of this prediction is to determinate the additional module redundancy of VSC and the used method is “binomial failure method”.
Abstract: Electrical impedance tomography (EIT) is an imaging method that is able to estimate the electrical conductivity distribution of living tissue. This work presents a field programmable gate array (FPGA)-based multi-frequency EIT system for complex, time-resolved bioimpedance measurements. The system has the capability to work with measurement setups with up to 16 current electrodes and 16 voltage electrodes. The excitation current has a range of about 10 µA to 5 mA, whereas the sinusoidal signal used for excitation can have a frequency of up to 500 kHz. Additionally, the usage of a chirp or rectangular signal excitation is possible. Furthermore, the described system has a sample rate of up to 3480 impedance spectra per second (ISPS). The performance of the EIT system is demonstrated with a resistor-based phantom and tank phantoms. Additionally, first measurements taken from the human thorax during a breathing cycle are presented.
Abstract: Flexible and transparent electronics have been studied intensively during the last few decades. The technique establishes the possibility of fabricating innovative products, from flexible displays to radio-frequency identification tags. Typically, large-area polymeric substrates such as polypropylene (PP) or polyethylene terephthalate (PET) are used, which produces new requirements for the integration processes. A key element for flexible and transparent electronics is the thin-film transistor (TFT), as it is responsible for the driving current in memory cells, digital circuits or organic light-emitting devices (OLEDs). In this paper, we discuss some fundamental concepts of TFT technology. Additionally, we present a comparison between the use of the semiconducting organic small-molecule pentacene and inorganic nanoparticle semiconductors in order to integrate TFTs suitable for flexible electronics. Moreover, a technique for integration with a submicron resolution suitable for glass and foil substrates is presented.