Oscar Alonso

Advancing towards smart endoscopy with specific electronics to enable locomotion and focusing capabilities in a wireless endoscopic capsule robot

The paper reports the electronics used in a new developed wireless endoscopic capsule provided with novel focus and locomotion features. The locomotion is enabled by using legs driven by 2 brushless DC (BLDC) micromotors. The focusing system is enabled by using a liquid lens with a variable focal. These functions are managed by an ASIC that has been developed to provide the specific innovative functions. The size of the ASIC is 3.0 mm × 2.7 mm in a 0.35 um high voltage CMOS technology. The ASIC is described in detail, as well as the performances when it is used with the final devices used in the capsule.

Crosstalk-Free Single Photon Avalanche Photodiodes Located in a Shared Well

Advances in single photon avalanche detector (SPAD) arrays propose improving the fill factor by confining several SPADs in the same well, with a main issue related to crosstalk. In applications that measure at fixed times, the pixels can be inhibited before the arrival of the crosstalk charge. This letter reports the crosstalk characterization in an array of SPADs, where the sensors share the same n-well (fill factor 67%), and fabricated in a conventional CMOS technology. The reduction of the gating time completely eliminates the crosstalk, as predicted by the theory and TCAD simulations.

Design of a brushless micro motor driver for a locomotive endoscopic capsule

In this paper is presented the design of a driver for a Namiki micro motor. The micro motor is used as a basic element for the locomotion of an endoscopic capsule to explore the entire gastrointestinal tract. The driver is based on the basic 3-phase structure with synchronous rectification and is designed in a full-custom ASIC in the h35 automotive technology of Austriamicrosystems.

Control electronics integration toward endoscopic capsule robot performing legged locomotion and illumination

Miniaturization of sensors and actuators up to the point of active features in endoscopic capsules, such as locomotion or surgery, is a challenge. VECTOR endoscopic capsule has been designed to be the first endoscopic capsule with active locomotion. It is equipped with mini-legs driven by Brushless DC (BLDC) micro motors. In addition it can be also equipped with some other sensors and actuators, like a liquid lens, that permits to enable advanced functions. Those modules are managed by an ASIC specifically designed for the VECTOR capsule. The ASIC is a complete System-On-Chip (SoC) and integrates all the electronics needed to enable the legged locomotion and the sensing and actuating functions of the capsule in an unique chip. The SoC also enables other functions for endoscopic capsules such as drug delivery and a biopsy system. The size of the SoC is 5.1 mm × 5.2 mm in a 0.35 um high voltage CMOS technology.

An optical interface for inter-robot communication in a swarm of microrobots

It is described the optical communication interface for short-range communications of robots in a microrobotic swarm between thousands of units. The robots, of 27 mm3-size, will be deployed in an arena of A4 sheet size with controlled illumination conditions. The communication between robots is done via IR light. The interface can handle variations of IR background light from point to point in the arena, deals with robot different orientation and distance, i.e., the amplitude of the signal to be detected, and with interferences of other robots. The interface has been designed to manage the low energy available in the robot.

Readout electronics for low dark count pixel detectors based on Geiger mode avalanche photodiodes fabricated in conventional CMOS technologies for future linear colliders

High sensitivity and excellent timing accuracy of the Geiger mode avalanche photodiodes make them ideal sensors as pixel detectors for particle tracking in high energy physics experiments to be performed in future linear colliders. Nevertheless, it is well known that these sensors suffer from dark counts and afterpulsing noise, which induce false hits (indistinguishable from event detection) as well as an increase in the necessary area of the readout system. In this work, we present a comparison between APDs fabricated in a high voltage 0.35 mm and a high integration 0.13 mm commercially available CMOS technologies that has been performed to determine which of them best fits the particle collider requirements. In addition, a readout circuit that allows low noise operation is introduced. Experimental characterization of the proposed pixel is also presented in this work.

An ultra low power IC for an autonomous mm 3 -sized microrobot

This paper is focused on the main issues of designing a SoC for a completely autonomous mm3-sized microrobot. It is described how all the electronics are included in a unique chip, the special requirements in the assembly process and how the hard constraints in power consumption are managed. Power in the robot is delivered by solar cells mounted on top and two supercapacitors which act as batteries. The maximum available energy for the SoC is 400 muW for driving the robot actuators and 1 mW for data processing. The special architecture of the SoC and power awareness are required to manage the very low available power.

Readout electronics for low dark count Geiger mode avalanche photodiodes fabricated in conventional HV-CMOS technologies for future linear colliders

This work presents low noise readout circuits for silicon pixel detectors based on Geiger mode avalanche photodiodes. Geiger mode avalanche photodiodes offer a high intrinsic gain as well as an excellent timing accuracy. In addition, they can be compatible with standard CMOS technologies. However, they suffer from a high intrinsic noise, which induces false counts indistinguishable from real events and represents an increase of the readout electronics area to store the false counts. We have developed new front-end electronic circuitry for Geiger mode avalanche photodiodes in a conventional 0.35 μm HV-CMOS technology based on a gated mode of operation that allows low noise operation. The performance of the pixel detector is triggered and synchronized with the particle beam thanks to the gated acquisition. The circuits allow low reverse bias overvoltage operation which also improves the noise figures. Experimental characterization of the fabricated front-end circuit is presented in this work.

Enabling multiple robotic functions in an endoscopic capsule for the entire gastrointestinal tract exploration

Commercial endoscopic capsules are passive. Nevertheless, active capabilities such as active locomotion, drug delivery or biopsy, among others, can now be offered with the aid of robotics. New robotic functions require additional electronics for control purposes, as well as for the sensors and actuators. To avoid increasing the capsule size as a consequence, it is useful to incorporate all the electronics into the minimum number of elements, preferably in a single ASIC. This paper describes the ASIC included in a robotised capsule with the abovementioned active functions. The ASIC is a system-on-chip (SoC) integrating all the electronics needed to control the other electronic elements in the capsule. It also enables the movement of two BLDC motors, illuminates the exploration region and focuses a liquid lens used to achieve advanced vision capabilities. Details of the complete system integration are also given.

An optically programmable SoC for an autonomous mm 3 -sized microrobot

A microrobot is a robot under a few cubic millimeters in size. Miniaturizing its components, power source, sensors and actuators, has proven challenging. As a consequence, few autonomous microrobots have been reported until recently [1–3]. These are simple mobile platforms, without sensors on board. Their electronics are basically focused on motion. I-SWARM is the first autonomous microrobot, 23mm3 and 70mg, designed to move, sense, take decisions, communicate and work in cooperation with other I-SWARM microrobots [4]. The area and weight of a microrobot are critical and limits the use of off-the-shelf components. So, it is required to integrate in a unique chip all the electronics, including the clock source, the POR and the voltage regulators.