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A new low-cost test method for analog integrated circuits, called the oscillation test, is presented. During the test mode, the circuit under test (CUT) is converted to a circuit that oscillates. Faults in the CUT which deviate the oscillation frequency from its tolerance band can be detected. Using this test method, no test vector is required to be applied. Therefore, the test vector generation problem is eliminated, and the test time is very small because only a single output frequency is evaluated for each CUT. The oscillation frequency may be considered as a digital signal and therefore can be evaluated using pure digital circuitry. These characteristics imply that the oscillation-test strategy is very attractive for wafer-probe testing as well as final production testing. In this note, the validity of the proposed test method has been verified throughout various examples such as operational amplifiers, amplifiers, filters, and analog-todigital converters (ADC's). The simulations and practical implementation results affirm that the presented method assures a high fault coverage.

Metallic nanohole arrays (NHAs) with a high hole density have emerged with potential applications for surface-enhanced Raman spectroscopy (SERS) including the detection of analytes at ultra-low concentrations. However, these NHA structures generally yield weak localized surface plasmon resonance (LSPR) which is a prerequisite for SERS measurements. In this work, a compact three-dimensional (3D) tunable plasmonic cavity with extraordinary optical transmission properties serves as a molecular sensor with sub-femtomolar detection. The 3D nanosensor consists of a gold film containing a NHA with an underlying cavity and a gold nanocone array at the bottom of the cavity. These nanosensors provide remarkable surface plasmon polariton (SPP) and LSPR coupling resulting in a significantly improved detection performance. The plasmonic tunability is evaluated both experimentally and theoretically. A SERS limit of detection of 10-16 M for 4-Nitrothiophenol (4-NTP) is obtained along with 28 distribution mapping of the molecule on the 3D plasmonic nanosensor. This results in an 29 improved SERS enhancement factor (EF) of 10 6 obtained from a femtolitre plasmonic cavity 30 volume. The tunability of these sensors can give rise to a potential opportunity for use in optical 31 trapping while providing SERS sensing of a molecule of interest. 32

We describe a new fabrication process utilizing polydimethylesiloxane (PDMS) as a sacrificial substrate layer for fabricating free-standing SU-8-based biomedical and microfluidic devices. The PDMS-on-glass substrate permits SU-8 photo patterning and layer-to-layer bonding. We have developed a novel PDMS-based process which allows the SU-8 structures to be easily peeled off from the substrate after complete fabrication. As an example, a fully enclosed microfluidic chip has been successfully fabricated utilizing the presented new process. The enclosed microfluidic chip uses adhesive bonding technology and the SU-8 layers from 10 µm to 450 µm thick for fully enclosed microchannels. SU-8 layers as large as the glass substrate are successfully fabricated and peeled off from the PDMS layer as single continuous sheets. The fabrication results are supported by optical microscopy and profilometry. The peel-off force for the 120 µm thick SU-8-based chips is measured using a voice coil actuator (VCA). As an additional benefit the release step leaves the input and the output of the microchannels accessible to the outside world facilitating interconnecting to the external devices.

This paper describes a new built-in self test (BIST) technique suitable for both functional and structural testing of analog and mixed-signal circuits based on the oscillation-test methodology. Analog-todigital converter (ADC) is used as a test vehicle to demonstrate the capability of the proposed OBIST technique for both functional and structural testing. Design of different parts of OBIST structure is also presented.The ADC conversion rate, differential nonlinearity (DNL) and integral nonlinearity (INL) at each quantization band edge (QBE) are tested as functional parameters. These parameters are considered to be the most important functional characteristics of an ADC.Practical experimentation using real-world successive approximation and flash ADCs confirms the accuracy of OBIST for functional testing of ADCs. Simulation results using a 3-bit flash ADC designed using a CMOS 1.2 pm technology are also presented. For structural testing, oversampled sigma-delta ADCs are investigated. Both hard and soft faults are considered and some simulation results are presented.

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