Tuning characteristics of mirrorlike T-shape terahertz metamaterial using out-of-plane actuated cantilevers

Yu-Sheng Lin and Chengkuo Lee

Abstract

We present a mirrorlike T-shape metamaterial (MTM) with out-of-plane movable microstructures for enabling active tuning of resonant frequency in the terahertz (THz) region. The resonant frequency of MTM device can be actively controlled by using either electrostaticforce or liquid force. First, by gradually increasing the bias, the cantilevers were continuously deformed towards the substrate and then completely snapped down when the bias reached the critical pull-in voltage (12 V). The tuning range is 0.50 THz as compared to the devicewithout driving voltage to that operated at the pull-in voltage. Meanwhile, we dropped different liquids on the snap-down device surface. In the case of device covered with deionised water, the resonant frequency shift of 0.17 and 0.21 THz were measured for inductive-capacitive and dipolar resonances, respectively. Furthermore, we also demonstrate the flow tuning capability of MTM device integrated with a polydimethylsiloxane fluidic channel by using different injection flow rate from 0 to 5 ml/min. The tunability of MTM device is 0.30 THz due to the different bending states of the MTM cantilevers under different liquid forces.

This study was performed using TeraView's TPS spectra 3000 system. (TeraView, Cambridge, UK)

Full Article: http://scitation.aip.org/content/aip/journal/apl/104/25/10.1063/1.4885839

ISTFA 2014 Oral Presentation Acceptance

TeraView are pleased to announce that we have had a the paper 'Non-Destructive Fault Isolation in Advanced IC Packages' accepted for oral presentation at ISTFA 2014!

This years event will be the 40th International Symposium for Testing and Failure Analysis, and will be held in Houston, Texas, November 9-13 2014.

ISTFA is where you’ll find researchers, engineers, technicians and others who work on discrete components, dies, wafer fabrication, packages, board assembly and systems. They’re your customers.

• ISTFA is the only international venue devoted to the semiconductor, electronic sample preparation and imaging markets.
• ISTFA attracts attendees from all major global geographic areas.
• ISTFA offers a comprehensive practical and theoretical technical program that attracts the broadest mix of attendees.
• ISTFA continually expands topic areas to attract new and diverse audiences.
• ISTFA provides two full days of dedicated expo hours – make connections, build relationships, and generate sales.

For more information on ISTFA 2014 please visit: 
http://www2.asminternational.org/content/Events/istfa/index.jsp

Temperature evolution of dielectric response spectra of stillwellite-like glasses in the terahertz and infrared ranges

G. A. Komandin, O. E. Porodinkov, Yu. G. Goncharov, I. E. Spektor, L. D. Iskhakova, V. N. Sigaev, S. V. Lotarev, V. I. Torgashev

Abstract

The reflectance and transmittance spectra of the PrBGeO5 glass were measured in the terahertz and infrared ranges. At low temperatures, an increase in the permittivity and the appearance of narrow resonance-type lines in the terahertz range were revealed. The complex permittivity spectra were calculated from the Fresnel and Kramers-Kronig formulas.

This study was performed using TeraView's TPS spectra 3000 system. (TeraView, Cambridge, UK)

Full Article: http://link.springer.com/article/10.1134/S106378341406016X

EPIC Workshop on Intra-Operative Assessment of Tumor-Resection Margins

TeraVeiw are pleased to announce that we will be in attendance at the 'EPIC Workshop on Intra-Operative Assessment of Tumor-Resection Margins'!

The event will be hosted at the Daniel den Hoed Clinic, the Erasmus-University Medical Centre in Rotterdam, The Netherlands on the 2nd-3rd of July 2014.

TeraView's Alessia Portieri will be in attendance at the event and will be giving a talk on 'THz intra-operative imaging' at 1:30 pm on the 2nd.


Agenda:

The draft program is being finalized, it includes speakers from Europe, USA, medical doctors, research organizations, and industrial companies.

Who Should Attend:
The workshop will bring together medical doctors, researchers pursuing image-guided / optical spectroscopy-guided surgery, and small and large companies able to offer suitable optical technologies. As for all EPIC events, a list of participants will be shared in advance, including a picture of each attendee and a description of their organization. 

Objective:
The aim is to:

• develop a common understanding of the exact needs and requirements of surgeons,
• constraints and challenges,
• document a roadmap on what technologies are currently available and what approaches should preferably be followed to develop and introduce photonic technologies in the operating room.

For more information on the event visit: http://epic-assoc.com/contact-us/?at=95

Assessment of Enamel Demineralisation and Remineralisation using Terahertz Pulsed Imaging

D. CHURCHLEY¹, F. LIPPERT², A. BUTLER¹, A. PORTIERI³, and R.J.M. LYNCH¹, ¹GlaxoSmithKline Consumer Healthcare, Weybridge, England, ²Indiana University School of Dentistry, Indianapolis, IN, ³TeraView Ltd, Cambridge, England

Objective

Transverse micro-radiography (TMR) is the “gold standard” for measuring mineral changes in enamel; however, it is destructive in nature. The aim of this study was to compare Terahertz Pulsed Imaging (TPI), a non-destructive technique, with TMR for measuring mineral changes in enamel.

Methods 

Lesions with diverse mineral characteristics were created in bovine and human enamel blocks (n=48 per enamel type) using three demineralising systems (MeC, Carbopol C907 & HEC).  Specimens were assigned to two treatment groups (n=24 per enamel type per group): Group 1: remineralisation for 5 days (1.5mM CaCl₂.2H₂O, 0.9mM KH₂PO₄, 20mM HEPES and 130mM KCl) Group 2: demineralisation for 2 days (50mM acetic acid, 2.25mM CaCl₂.2H₂O, 1.35mM KH₂PO₄, 130mM KCl and 5ppm F).  Lesions were imaged using a TPI imaga 1000. Reflection data were used to generate lesion mineral profiles.   Lesions were also radiographed.  For both techniques the integrated mineral loss (ΔZ), lesion depth (L), change in mineral content (ΔM), and change in lesion depth (ΔL) were calculated. Pearson correlation coefficients were calculated for the combined data set as well as by enamel type, treatment and lesion type.

Results

The table shows the Pearson correlation coefficients.  There is generally a good association (Pearson coefficients ≥ 0.70) between TPI and TMR measurements for most variables.

Variable	Combined	Enamel Type		Treatment		Lesion Type
		Bovine	Human	Demin	Remin	MeC	C907	HEC
ΔZ(baseline)	0.66	0.69	0.65	0.59	0.81	0.28	0.74	0.47
ΔZ(post-treatment)	0.84	0.92	0.71	0.78	0.83	0.82	0.82	0.77
ΔM	0.75	0.84	0.58	0.55	0.52	0.80	0.72	0.70
L(baseline)	0.79	0.77	0.80	0.76	0.87	0.19	0.75	0.20
L(post-treatment)	0.88	0.95	0.77	0.75	0.73	0.97	0.87	0.78
ΔL	0.84	0.93	0.65	0.49	0.51	0.94	0.80	0.82

Conclusion 

Whilst these initial findings demonstrate that TPI could be a useful technique for the non-destructive assessment of enamel mineral changes; further evaluation is required.

This study was performed using TeraView's Imaga 1000 system (TeraView, Cambridge, UK) 

Full Article: https://iadr.confex.com/iadr/14iags/webprogram/Paper189313.html