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Re-engineering Artificial Muscle with Microhydraulics

June 5, 2017
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Journal Article
Author:
Jakub T. Kedzierski
…
Published in:
Nature Microsystems & Nanoengineering, vol. 3
Topic:
microfluidics
R&D area:
R&D group:

Summary

We introduce a new type of actuator, the microhydraulic stepping actuator (MSA), which borrows design and operational concepts from biological muscle and stepper motors. MSAs offer a unique combination of power, efficiency, and scalability not easily achievable on the microscale. The actuator works by integrating surface tension forces produced by electrowetting acting on scaled droplets along the length of a thin ribbon. Like muscle, MSAs have liquid and solid functional components and can displace a large
fraction of their length. The 100 μm pitch MSA presented here already has an output power density of over 200 W kg− 1, rivaling the most powerful biological muscles, due to the scaling of surface tension forces, MSA’s power density grows quadratically as its dimensions are reduced.
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Summary

We introduce a new type of actuator, the microhydraulic stepping actuator (MSA), which borrows design and operational concepts from biological muscle and stepper motors. MSAs offer a unique combination of power, efficiency, and scalability not easily achievable on the microscale. The actuator works by integrating surface tension forces produced by...

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Re-engineering Artificial Muscle with Microhydraulics

Aircraft laser strike geolocation system

June 5, 2017
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Conference Paper
Author:
Erin M. Tomlinson
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Published in:
17th AIAA Aviation Technology, Integration, and Operations Conf., 5-9 June 2017.
Topic:
detection systems
R&D area:
R&D group:

Summary

Laser strikes against aircraft are increasing at an alarming rate, driven by the availability of cheap powerful lasers and a lack of deterrence due to the challenges of locating and apprehending perpetrators. Although window coatings and pilot goggles effectively block laser light, uptake has been low due to high cost and pilot reluctance. This paper describes the development and testing of a proof-of-concept ground based sensor system to rapidly geolocate the origin of a laser beam in a protected region of airspace and disseminate this information to law enforcement to allow a timely and targeted response. Geolocation estimates with accuracies of better than 20 m have been demonstrated within 30 seconds of an event at a range of 8.9 nmi with a 450 mW laser. Recommendations for an operational prototype at an airport are also described.
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Summary

Laser strikes against aircraft are increasing at an alarming rate, driven by the availability of cheap powerful lasers and a lack of deterrence due to the challenges of locating and apprehending perpetrators. Although window coatings and pilot goggles effectively block laser light, uptake has been low due to high cost...

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Aircraft laser strike geolocation system

A polarization technique for mitigating low-grazing-angle radar sea clutter

June 4, 2017
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Conference Paper
Author:
Molly K. Crane
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Published in:
IEEE Int. Microwave Symp., 4-9 June 2017.
Topic:
radar
R&D area:
R&D group:

Summary

Traditional detection schemes in conventional maritime surveillance radars may suffer serious performance degradation due to sea clutter, particularly in low-grazing-angle (LGA) geometries. In such geometries, typical statistical assumptions regarding sea clutter backscatter do not hold. Trackers can be overwhelmed by false alarms, while objects of interest can be challenging to detect. Despite several decades of attempts to devise a means of mitigating the effects of LGA sea clutter on traditional detection schemes, minimal progress has been made in developing an approach that is both robust and practical. To supplement work exploring whether polarization information might offer an effective means of enhancing target detection in sea clutter, MIT Lincoln Laboratory (MIT LL) collected a fully polarimetric X-band radar dataset on the Atlantic coast of Massachusetts Cape Ann in October 2015. Leveraging this dataset, MIT LL developed Polarimetric Co-location Layering (PCL), an algorithm that uses a fundamental polarimetric characteristic of sea clutter to retain detections on objects of interest while reducing the number of false alarms in a conventional singlepolarization radar by as many as two orders of magnitude. PCL is robust across waveform bandwidths, pulse repetition frequencies, and sea states. Moreover, PCL is practical: It can plug directly into the standard radar signal processing chain.
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Summary

Traditional detection schemes in conventional maritime surveillance radars may suffer serious performance degradation due to sea clutter, particularly in low-grazing-angle (LGA) geometries. In such geometries, typical statistical assumptions regarding sea clutter backscatter do not hold. Trackers can be overwhelmed by false alarms, while objects of interest can be challenging to...

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A polarization technique for mitigating low-grazing-angle radar sea clutter

Report on the 2016 CoSPA and Traffic Flow Impact operational demonstration

June 1, 2017
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Project Report
Author:
Joseph C. Venuti
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Published in:
MIT Lincoln Laboratory Report ATC-433
Topic:
weather
R&D area:
R&D group:

Summary

This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 1 June to 31 October 2016. The MIT LL observation team visited three Federal Aviation Administration (FAA) Air Route Traffic Control Centers (ARTCC) and the Air Traffic Control System Command Center (ATCSCC) on three separate convective events covering four days during the summer of 2016. Five commercial airlines were also involved in the observations. Specifically noted were the utilization of the deterministic convective weather forecasting model, Storm Prediction for Aviation (CoSPA), and a newly developed decision support application, Traffic Flow Impact (TFI). These field evaluations were supported via the FAA AJM-334 program.
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Summary

This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 1 June to 31 October 2016. The MIT LL observation team visited three Federal Aviation Administration (FAA) Air Route Traffic Control Centers (ARTCC) and the Air Traffic Control System...

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Report on the 2016 CoSPA and Traffic Flow Impact operational demonstration

Germanium CCDs for large-format SWIR and x-ray imaging

May 25, 2017
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Journal Article
Author:
Christopher W. Leitz
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Published in:
J. Instrum., Vol. 12, No. 5, May 2017, C05014.
Topic:
photonics
R&D area:
R&D group:

Summary

Germanium exhibits high sensitivity to short-wave infrared (SWIR) and X-ray radiation, making it an interesting candidate for imaging applications in these bands. Recent advances in germanium processing allow for high-quality charge-coupled devices (CCDs) to be realized in this material. In this article, we discuss our evaluation of germanium as an absorber material for CCDs via fabrication and analysis of discrete devices such as diodes, metal-insulator-semiconductor capacitors, and buried-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). We then describe fabrication of our first imaging device on germanium, a 32 x 1 x 8.1 um linear shift register. Based on this work, we find that germanium is a promising material for CCDs imaging in the SWIR and X-ray bands.
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Summary

Germanium exhibits high sensitivity to short-wave infrared (SWIR) and X-ray radiation, making it an interesting candidate for imaging applications in these bands. Recent advances in germanium processing allow for high-quality charge-coupled devices (CCDs) to be realized in this material. In this article, we discuss our evaluation of germanium as an...

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Germanium CCDs for large-format SWIR and x-ray imaging

Raman Detection of a Single Airborne Aerosol Particles of Isovanillin(3.09 MB)

May 24, 2017
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Journal Article
Author:
Roshan L. Aggarwal
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Published in:
AIP Advances, vol. 7, no. 5
Topic:
chemical technologies
R&D area:
R&D group:

Summary

Raman spectroscopy of trapped single aerosol particles has been reported previously. However, detection of single aerosol particles via Raman spectroscopy in a flowing system has not been yet reported. In this paper, we describe the first detection of single 3 um flowing airborne aerosol particles flowing through a Raman system, which is a simplified version of the previously reported system with a 532-nm, 10W cw double-pass laser, 532-nm isolator, and double-sided collection optics. The current system has single-pass laser, no 532-nm isolator, and single-sided collection optics. Previous Raman detection of single aerosol particles has been made using trapped particles.
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Summary

Raman spectroscopy of trapped single aerosol particles has been reported previously. However, detection of single aerosol particles via Raman spectroscopy in a flowing system has not been yet reported. In this paper, we describe the first detection of single 3 um flowing airborne aerosol particles flowing through a Raman system...

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Raman Detection of a Single Airborne Aerosol Particles of Isovanillin

SoK: cryptographically protected database search

May 22, 2017
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Conference Paper
Author:
Benjamin W. Fuller
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Published in:
IEEE Symp. on Security and Privacy, 22-26 May 2017.
Topic:
cryptography
R&D area:
R&D group:

Summary

Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly, systems are offered by academia, start-ups, and established companies. However, there is no best protected search system or set of techniques. Design of such systems is a balancing act between security, functionality, performance, and usability. This challenge is made more difficult by ongoing database specialization, as some users will want the functionality of SQL, NoSQL, or NewSQL databases. This database evolution will continue, and the protected search community should be able to quickly provide functionality consistent with newly invented databases. At the same time, the community must accurately and clearly characterize the tradeoffs between different approaches. To address these challenges, we provide the following contributions:(1) An identification of the important primitive operations across database paradigms. We find there are a small number of base operations that can be used and combined to support a large number of database paradigms.(2) An evaluation of the current state of protected search systems in implementing these base operations. This evaluation describes the main approaches and tradeoffs for each base operation. Furthermore, it puts protected search in the context of unprotected search, identifying key gaps in functionality.(3) An analysis of attacks against protected search for different base queries.(4) A roadmap and tools for transforming a protected search system into a protected database, including an open-source performance evaluation platform and initial user opinions of protected search.
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Summary

Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly, systems are offered by academia, start-ups...

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SoK: cryptographically protected database search

Strong effect of azodye layer thickness on RM-stabilized photoalignment

May 21, 2017
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Conference Paper
Author:
Colin P. McGinty
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Published in:
SID Symp. Digest of Tech. Papers, Vol. 48, No. 1, May 2017, pp. 578-81.
Topic:
photonics
R&D area:
R&D group:

Summary

We have previously proposed a process for stabilizing azodye photo-alignment layers using a surface localized reactive mesogen (RM) layer applied by dissolving the monomer in a liquid crystal prior to filling the cell. Surprisingly, thin azodye layers (~3 nm) exhibit improved stability upon exposure to polarized light compared to thicker layers (~40 nm).
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Summary

We have previously proposed a process for stabilizing azodye photo-alignment layers using a surface localized reactive mesogen (RM) layer applied by dissolving the monomer in a liquid crystal prior to filling the cell. Surprisingly, thin azodye layers (~3 nm) exhibit improved stability upon exposure to polarized light compared to thicker...

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Strong effect of azodye layer thickness on RM-stabilized photoalignment

Broadband transparent optical phase change materials

May 14, 2017
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Conference Paper
Author:
Yifei Zhang
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Published in:
CLEO: Conf. on Lasers and Electro-Optics, 14-19 May 2017.
Topic:
optics
R&D area:
R&D group:

Summary

We report a new group of optical phase change materials Ge-Sb-Se-Te (GSST) with low loss from telecom bands to LWIR. We further demonstrated GSST-integratedSiN photonics with significantly improved switching performance over conventional GST alloys.
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Summary

We report a new group of optical phase change materials Ge-Sb-Se-Te (GSST) with low loss from telecom bands to LWIR. We further demonstrated GSST-integratedSiN photonics with significantly improved switching performance over conventional GST alloys.

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Broadband transparent optical phase change materials

Fabrication security and trust of domain-specific ASIC processors

May 1, 2017
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Conference Paper
Author:
Mankuan Michael Vai
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Published in:
IEEE Intl. Symp. on Hardware Oriented Security and Trust, HOST, 1-5 May 2017.
Topic:
algorithms
R&D area:
R&D group:

Summary

Application specific integrated circuits (ASICs) are commonly used to implement high-performance signal-processing systems for high-volume applications, but their high development costs and inflexible nature make ASICs inappropriate for algorithm development and low-volume DoD applications. In addition, the intellectual property (IP) embedded in the ASIC is at risk when fabricated in an untrusted foundry. Lincoln Laboratory has developed a flexible signal-processing architecture to implement a wide range of algorithms within one application domain, for example radar signal processing. In this design methodology, common signal processing kernels such as digital filters, fast Fourier transforms (FFTs), and matrix transformations are implemented as optimized modules, which are interconnected by a programmable wiring fabric that is similar to the interconnect in a field programmable gate array (FPGA). One or more programmable microcontrollers are also embedded in the fabric to sequence the operations. This design methodology, which has been termed a coarse-grained FPGA, has been shown to achieve a near ASIC level of performance. In addition, since the signal processing algorithms are expressed in firmware that is loaded at runtime, the important application details are protected from an unscrupulous foundry.
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Summary

Application specific integrated circuits (ASICs) are commonly used to implement high-performance signal-processing systems for high-volume applications, but their high development costs and inflexible nature make ASICs inappropriate for algorithm development and low-volume DoD applications. In addition, the intellectual property (IP) embedded in the ASIC is at risk when fabricated in...

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Fabrication security and trust of domain-specific ASIC processors
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