In the summer of 2013, I started working with Natalie Rechberg on Daysy and DaysyView. Daysy is an intelligent fertility monitor that allows women to track their menstrual cycle. For more information, check out http://daysy.ch.
This was a 6-month research and development project where I worked as project manager and principal engineer in the design and implementation for automating flow bacterial measurements of drinking water using flow cytometry with Frederik Hammes, Hans-Ulrich Weilenmann, and Michael Besmer at Eawag. The project involved the design, manufacturing, verification, and validation of the online (DOFCM) and real-time (RTFCM) flow cytometer prototypes, and was probably one of the most enjoyable projects I've ever worked on.
In 2010, I co-founded Aeon Scientific AG with Brad Nelson, Dominik Bell, and Dominic Frutiger. The company's goal is to develop magnetic catheter steering technologies for the treatment of arrhythmias, such as atrial fibrillation. It allows them to move the ablation catheter within the heart of the patient with magnetic fields. The improved control leads to better outcomes, reduced treatment costs and a higher number of patients that can be treated. In my role as CTO, I managed the design, construction, and testing of the first prototype within 24 months of the initial product conception.
In 2009, I began supervision of the ophthalmic microrobot project at IRIS. The project was spearheaded by Jake Abbott and Michael Kummer, and my contribution primarily dealt with system design, integration, and implementation. The resultant system was the Octomag, which allows for five-degree-of-freedom (5-DOF) wireless magnetic control of a fully untethered device (3-DOF position, 2-DOF pointing orientation).
The OctoMag is a prototype system for steering intra-ocular drug release inserts to treat a variety of retinal diseases over extended time periods. The addition of mobility to intraocular inserts allows a greater degree of spatial precision when treating diseases, which in turn enables the reduction of drug concentrations and dosing frequency and helps minimize side effects and invasiveness.
The MiniMag is a desktop version of the OctoMag capable of 5 degree-of-freedom (5-DOF) wireless magnetic control of an untethered agent (3-DOF position, 2-DOF pointing orientation) within a spherical workspace with 10 mm diameter.
The micromanipulation systems come in two forms. An upright version is designed for use with a standard optical microscope and allows for a completely unrestricted workspace above the manipulator for the addition of items such as probes or fluidic equipment. This system can be readily equipped with a dual microscope setup which allows for three-dimensional visual feedback of the manipulation task. The inverted micromanipulation system is designed for use with an inverted and/or fluorescent microscope. With the use of fluorescence nanometer-scale objects can be manipulated.The system was demonstrated as part of the 2010 NIST Microrobotics Challenge and won 2 out of three divisions.
Primary challenges in the building of untethered sub-millimeter sized
robots include propulsion methods, power supply, and control. In 2006, a call for participants was given for the new RoboCup Nanogram competition. Karl Vollmers, Dominic Frutiger, and I decided that if our groups was going to be researching microrobotics, we should field a team. In less than 9 months, we developed a novel
type of microrobot termed Magmite that utilizes a new class of Wireless Resonant
Magnetic Micro-actuator (WRMMa) which accomplishes all three tasks.
device harvests magnetic energy from the environment and ectively transforms it
into impact-driven mechanical force while being fully controllable. It can be powered
and controlled with oscillating fields in the kHz range and strengths as low as 2 mT,
which is only roughly 50 times the average earth magnetic field. These microrobotics
agents with dimensions less than 300 um x 300 um x 70 um are capable of moving
forward, backward and turning in place while reaching speeds in excess of 12.5 mm/s
or 42 times the robot's body length per second. The robots produce enough force
to push 150 um x 20 um gold disks and can be visually servoed through a maze in
a fully automated fashion.
The robustness of our robots and systems leads to high experimental repeatability, which in turn enabled us to win the RoboCup 2007 and 2009 Nanogram Competitions.
Robotics continues to provide researchers with an increasing ability to interact with objects at the nanoscale. As micro- and nanorobotic technologies mature, more interest is given to computer-assisted or automated approaches to manipulation. Although actuators are currently available that enable displacement resolutions in the subnanometer range, improvements in feedback technologies have not kept pace. Thus, many actuators that are capable of performing nanometer displacements are limited in automated tasks by the lack of suitable feedback mechanisms. My work proposes the use of a rigid-model-based method for end effector tracking in a scanning electron microscope to aid in enabling more precise automated manipulations and measurements. These models allow the system to leverage domain-specific knowledge to improve performance in a challenging tracking environment.
Few rotational actuators currently exist with the ability to transmit motion at different speeds, torques, and directions at the nanometer scale. We have worked to apply helical nanobelts as linear-to-rotary and rotary-to-linear motion converters. This conversion is based upon their ability to rectify device rotation to linear motion for untethered microrobotic applications as well as their application as rotary sample stages for nanoscale imaging.