Muhammad Mujeeb-U-Rahman

An implantable continuous glucose monitoring microsystem in 0.18µm CMOS

We present a fully implantable subcutaneous continuous glucose monitoring (CGM) microsystem on CMOS platform. The proposed design incorporates electrochemical sensing technique using an ultra-low-power potentiostatic system. It is wirelessly powered through an inductive coupling link at 900MHz and supports bidirectional data communication with an external reader. A low-power potentiostat and a dual-slope ADC record the on-chip sensor signal. Pt and Ag/AgCl on-chip electrodes are post-fabricated and functionalized in situ by glucose oxidase enzyme to enable glucose measurement. The 1.4×1.4×0.25mm3 prototype fabricated in a 0.18μm CMOS technology was validated in glucose measurements. Total power consumption of the system is 6μW.

Experimental demonstration of a reconfigurable silicon thermo-optical device based on spectral tuning of ring resonators for optical signal processing

We have experimentally demonstrated a reconfigurable silicon thermo-optical device able to tailor its intrinsic spectral optical response by means of the thermo-optical control of individual and uncoupled resonant modes of micro-ring resonators. Preliminarily results show that the devices optical response can be tailored to build up distinct and reconfigurable logic levels for optical signal processing, as well as control of overall figures of merit, such as free-spectral-range, extinction ratio and 3 dB bandwidth. In addition, the micro-heaters on top of the ring resonators are able to tune the resonant wavelength with efficiency of 0.25 nm/mW within a range of up to 10 nm, as well as able to switch the resonant wavelength within fall and rise time of 15 μs.

Optical power transfer and communication methods for wireless implantable sensing platforms

Abstract. Ultrasmall scale implants have recently attracted focus as valuable tools for monitoring both acute and chronic diseases. Semiconductor optical technologies are the key to miniaturizing these devices to the long-sought sub-mm scale, which will enable long-term use of these devices for medical applications. This can also enable the use of multiple implantable devices concurrently to form a true body area network of sensors. We demonstrate optical power transfer techniques and methods to effectively harness this power for implantable devices. Furthermore, we also present methods for optical data transfer from such implants. Simultaneous use of these technologies can result in miniaturized sensing platforms that can allow for large-scale use of such systems in real world applications.

Fabrication of Patterned Integrated Electrochemical Sensors

Fabrication of integrated electrochemical sensors is an important step towards realizing fully integrated and truly wireless platforms for many local, real-time sensing applications. Micro/nanoscale patterning of small area electrochemical sensor surfaces enhances the sensor performance to overcome the limitations resulting from their small surface area and thus is the key to the successful miniaturization of integrated platforms. We have demonstrated the microfabrication of electrochemical sensors utilizing top-down lithography and etching techniques on silicon and CMOS substrates. This choice of fabrication avoids the need of bottom-up techniques that are not compatible with established methods for fabricating electronics (e.g., CMOS) which form the industrial basis of most integrated microsystems. We present the results of applying microfabricated sensors to various measurement problems, with special attention to their use for continuous DNA and glucose sensing. Our results demonstrate the advantages of using micro- and nanofabrication techniques for the miniaturization and optimization of modern sensing platforms that employ well-established electronic measurement techniques.

Optical methods for wireless implantable sensing platforms

Ultra small scale implants have gained lots of importance for both acute and chronic applications. Optical techniques hold the key to miniaturizing these devices to long sought sub-mm scale. This will lead towards long term use of these devices for medically relevant applications. It can also allow using multiple of these devices at the same time and forming a true body area network of sensors. In this paper, we present optical power transfer to such devices and the techniques to harness this power for different applications, for example high voltage or high current applications. We also present methods for wireless data transfer from such implants.

A novel semiconductor based wireless electrochemical sensing platform for chronic disease management

Electrochemical sensors are very versatile and can be used for a diverse range of biomedical applications. In this paper, a novel fully-integrated wireless electrochemical sensing platform is presented. The platform uses standard semiconductor technology to create a miniaturized integrated bioelectronics system that consists of an electrochemical sensor, potentiostat, signal processing circuitry, wireless power harvesting circuitry, and wireless telemetry unit, all on a single microchip. The platform is orders of magnitude smaller than the state-of-the-art sensing systems and costs a fraction. At 1.4 mm × 1.4 mm size, the sensor costs less than

Design and fabrication of implantable fully integrated electrochemical sensors

1 to manufacture. The presented design provides fundamental advantages in decreasing sensor noise and settling time, thus providing superior response compared to existing solutions. System design and implementation details are presented as well as examples for metabolic sensing (glucose, lactate, O2) applications. The system can have widespread applications in biosensing applications.