Cristina Lerma Arce

Silicon photonic sensors incorporated in a digital microfluidic system

AbstractLabel-free biosensing with silicon nanophotonic microring resonator sensors has proven to be an excellent sensing technique for achieving high-throughput and high sensitivity, comparing favorably with other labeled and label-free sensing techniques. However, as in any biosensing platform, silicon nanophotonic microring resonator sensors require a fluidic component which allows the continuous delivery of the sample to the sensor surface. This component is typically based on microchannels in polydimethylsiloxane or other materials, which add cost and complexity to the system. The use of microdroplets in a digital microfluidic system, instead of continuous flows, is one of the recent trends in the field, where microliter- to picoliter-sized droplets are generated, transported, mixed, and split, thereby creating miniaturized reaction chambers which can be controlled individually in time and space. This avoids cross talk between samples or reagents and allows fluid plugs to be manipulated on reconfigurable paths, which cannot be achieved using the more established and more complex technology of microfluidic channels where droplets are controlled in series. It has great potential for high-throughput liquid handling, while avoiding on-chip cross-contamination. We present the integration of two miniaturized technologies: label-free silicon nanophotonic microring resonator sensors and digital microfluidics, providing an alternative to the typical microfluidic system based on microchannels. The performance of this combined system is demonstrated by performing proof-of-principle measurements of glucose, sodium chloride, and ethanol concentrations. These results show that multiplexed real-time detection and analysis, great flexibility, and portability make the combination of these technologies an ideal platform for easy and fast use in any laboratory. Online Abstract FigureDroplet moving on the surface a photonic chip with a digital microfluidic system

Broadband and non-volatile liquid controlled silicon photonics switch

A broadband and non-volatile liquid controlled silicon photonics switch is proposed. The measured crosstalk is less than -22dB and -12dB over 100nm wavelength range for bar and cross state, respectively. The insertion loss is less than 1dB.

Silicon photonics biosensing: different packaging platforms and applications

We present two different platforms integrating silicon photonic biosensors. One is based on integration with reaction tubes to be compatible with traditional lab approaches. The other uses through-chip fluidics in order to achieve better mixing of the analyte.

SOI Microring Resonator Sensor Integrated on a Fiber Facet

The application of optical fiber technology for sensing has undergone tremendous growth over the last years. Its use for imaging hard-to-reach locations and its property to conduct light to a remote convenient location make of it a suitable tool for in vivo sensing applications, such as endoscopy. Here, we present an optical fiber probe sensor for label-free biosensing based on SOI ring resonators. We describe the operating principle of the device, the technology used to integrate a Silicon-on-insulator (SOI) chip on a fiber facet and discuss some experimental results.

Reaction tubes as a platform for silicon nanophotonic ring resonator biosensors

We propose the combination of a simple reaction tube platform with label free SOI photonic biosensors. The device allows for the excellent performance of ring resonator sensors in a user-friendly platform to be used in labs and hospitals.