• Jeffers N.
  • Punch J.
  • Stafford J.
  • Waddell A.

Photonics Integrated Circuits (PICs) are being deployed by the telecommunications industry as transceivers for fibre optic networks. The core component of a typical PIC is the laser-array and the power density of these devices (102 W/cm2 ) now demands novel thermal management architectures including developments such as near-source liquid cooling. In such a system, thermal control is required through feedback and for this a micro-valve could be developed from the NiTi Shape Memory Alloy (SMA). Thermally coupled to the laser-array this micro-valve would work passively to regulate the flow of coolant in a micro-channel. The objective of the work is to realize a passive SMA valve at the millimetre scale, and to characterise this valve in a mini-channel. A prototype valve was designed and fabricated from 127 µm thick stainless steel sheet and 0.4 mm NiTi actuator wire. Experiments were conducted to observe the actuation of the valve and measure its hydro-dynamic characteristics. The results demonstrate that the valve is capable of actuating passively in response to the temperature of the flow in the channel. The proposed design was capable of completing 80% of the total valve movement in under two seconds, highlighting the capabilities of SMA valves for dynamic passive control. The pressure drop was 20-100 Pa for a range of Reynolds numbers between 100 and 220. The pressure drop measurements were then used to calculate the loss coefficient for the valve (K). This body of work takes a significant step towards realizing a passive NiTi SMA micro-valve.

Recent Publications

August 09, 2017

A Cloud Native Approach to 5G Network Slicing

  • Francini A.
  • Miller R.
  • Sharma S.

5G networks will have to support a set of very diverse and often extreme requirements. Network slicing offers an effective way to unlock the full potential of 5G networks and meet those requirements on a shared network infrastructure. This paper presents a cloud native approach to network slicing. The cloud ...

August 01, 2017

Modeling and simulation of RSOA with a dual-electrode configuration

  • De Valicourt G.
  • Liu Z.
  • Violas M.
  • Wang H.
  • Wu Q.

Based on the physical model of a bulk reflective semiconductor optical amplifier (RSOA) used as a modulator in radio over fiber (RoF) links, the distributions of carrier density, signal photon density, and amplified spontaneous emission photon density are demonstrated. One of limits in the use of RSOA is the lower ...

July 12, 2017

PrivApprox: Privacy-Preserving Stream Analytics

  • Chen R.
  • Christof Fetzer
  • Le D.
  • Martin Beck
  • Pramod Bhatotia
  • Thorsten Strufe

How to preserve users' privacy while supporting high-utility analytics for low-latency stream processing? To answer this question: we describe the design, implementation and evaluation of PRIVAPPROX, a data analytics system for privacy-preserving stream processing. PRIVAPPROX provides three properties: (i) Privacy: zero-knowledge privacy (ezk) guarantees for users, a privacy bound tighter ...