Eric D. Diller

• PhD
• Professor (Assistant) at University of Toronto

Decades of efforts have been made to minimize the invasiveness of the procedures inside the patient’s brain. Endoscopic tools are first developed and applied in neurosurgery, which significantly reduce the trauma to a limited number of small holes but also limit the surgeon’s reachability to the target tissue inside of the brain due to the tool’s r...

Untethered magnetically actuated robots present significant advantages for biomedical applications by allowing power to be delivered wirelessly to remote, miniature robots through flesh and bone. Nevertheless, generating enough usable force to interact with their environment remains a challenge: Most millimeter-size magnetic robots achieve forces o...

We propose a robotics method to independently control the position of multiple magnetic microrobots (agents) through their local magnetic interactions in close proximity. Utilizing a rapidly-exploring random tree (RRT) planner, we generate a trajectory which is then followed by an optimization-based controller (OBC), while avoiding obstacles. The m...

Wireless robots at the subcentimeter size are often actuated using externally generated magnetic fields. For most applications, these remote magnetic microrobots are located relatively far from the magnetic field generation sources. In this condition, all microrobots receive approximately the same driving magnetic field (which we term a homogeneous...

This article presents a method to independently control the position of multiple microscale magnetic robots in three dimensions, operating in close proximity to each other. Having multiple magnetic microrobots work together in close proximity is difficult due to magnetic interactions between the robots, and here we aim to control those interactions...

Robot-assisted minimally invasive surgical (MIS) techniques offer improved instrument precision and dexterity, reduced patient trauma and risk, and promise to lessen the skill gap among surgeons. These approaches are common in general surgery, urology, and gynecology. However, MIS techniques remain largely absent for surgical applications with narr...

Mechanical loading on bone tissue is an important physiological stimulus that plays a key role in bone growth, fracture repair, and treatment of bone diseases. Osteocytes (bone cells embedded in bone matrix) are well accepted as the sensor cells to mechanical loading and play a critical role in regulating the bone structure in response to mechanica...

The goal of this article is to provide a thorough introduction to the state of the art in magnetic methods for remote-manipulation and wireless-actuation tasks in robotics. The article synthesizes prior works using a unified notation, enabling straightforward application in robotics. It begins with a discussion of the magnetic fields generated by m...

Remote-controlled minimally invasive neuroendoscopic robotic surgical tools can be miniaturized to a size of less than 2 mm while maintaining their dexterity and force required to perform operations in brain without an open-skull surgery. However, these platforms lack haptic information to be received by the surgeons, leading to loss of control ove...

For further details refer to: https://ieeexplore.ieee.org/document/8860954

Recent studies on concentric tube robots (CTRs) have shown that they are well-suited for minimally invasive endoscopic surgeries. However, typical surgical procedures require the use of multiple tools simultaneously which has led to the development of dual-arm CTRs that are susceptible to self-collision. In this paper, a closed-loop control system...

Flexible magnetic small-scale robots use patterned magnetization to achieve fast transformation into complex three-dimensional (3D) shapes and thereby achieve locomotion capabilities and functions. These capabilities address current challenges for microrobots in drug delivery, object manipulation, and minimally invasive procedures. However, possibl...

This paper introduces new strategy for motion control of two spinning magnetic agents based on the magnetic-fluidic interactions. The approach relies on balance between magnetic attraction and hydrodynamic repulsion forces created by fluidic vortices around pairs of microagents, which allows the control on inter-agent pair heading and spacing. The...

Precise and dexterous handling of micrometer to millimeter-scale objects are the two key and challenging factors for mincromanipualtion, especially in the fields of biotechnology where delicate microcomponents can be easily damaged by contact during handling. Many complex microrobotic techniques, scaling from fully autonomous to teleoperated, have...

In this letter, a novel end-effector for surgical applications is presented that uses magnetic actuation in lieu of a more traditional cable-driven tool with the goal of providing high dexterity in hard-to-reach locations by decoupling the tool actuation from the rest of the surgical system. The gripper and wrist device consists of several magnets...

Pin-jointed wrist mechanisms provide compact articulation for surgical robotic applications, but are difficult to miniaturize at scales suitable for small body cavity surgery. Solid surface cable guide channels, which eliminate the need for pulleys and reduce overall length to facilitate miniaturization, were developed within a three-degree-of-free...

The actuation and control of miniature soft robots are challenging problems due to their limited onboard space and flexible bodies. Smart magnetic materials are promising candidates to address these challenges since they can be powered and guided remotely by magnetic field for functionalities, such as swimming, grasping, and pumping. In this study,...

This paper overviews two different approaches in individually addressing multiple motions for small-scale magnetic systems where the controlling signals are provided through a generic quasistatic homogeneous magnetic field. The first approach relies on direct independent magnetic actuation of multiple DOFs to make dexterous microdevices. The second...

Untethered mobile microgrippers exhibit flexibility and agility in small and constrained environments as precise and accurate robotic end-effectors, with promising potential applications in cell manipulation and microassembly. Here, we propose the first scheme to independently and simultaneously position two microgrippers on a horizontal plane for...

The generation of microparticles with non-spherical morphologies has generated extensive interest because of their enhanced physical properties that can increase their performance in a wide variety of clinical and industrial applications. A flow lithographic technique based on stop flow lithography (SFL) recently shows the ability to fabricate part...

Recent work in magnetically actuated microscale robots for biomedical or microfluidic applications has resulted in magnetic actuation systems that can remotely command precise five-degree-of-freedom control of magnetic devices. This paper presents a new type of actuation system, which uses an array of rotating permanent magnets to generate the same...

This paper presents a new optimization-based method to control three micro-scale magnetic agents operating in close proximity to each other for applications in microrobotics. Controlling multiple magnetic microrobots close to each other is difficult due to magnetic interactions between the agents, and here we seek to control those interactions for...

This paper presents a new method to control multiple micro-scale magnetic agents operating in close proximity to each other for applications in microrobotics. Controlling multiple magnetic microrobots close to each other is difficult due to magnetic interactions between the agents, and here we seek to control those interactions for the creation of...

Cell sorters play important roles in biological and medical applications, such as cellular behavior study and disease diagnosis and therapy. This work presents a label-free microfluidic sorter that has a downstream-pointing magnetic elastic diverter. Different with most existing magnetic sorters, the proposed device does not require the target micr...

In this article, we present a new three-dimensional printing inspired method for in situ fabrication of mobile magnetic microrobots with complex topology by bending a polymer filament on demand directly inside an enclosed operational environment. Compared with current microrobot fabrication methods that typically involve multiple microfabrication s...

Manipulation of micrometer to millimeter-scale objects is central to bio-technological and medical applications involving small-scale robotic devices. Mobile untethered microgrippers have been developed, which use magnetic fields for motion and activation of grasping. This paper extends the capabilities of such microgrippers by presenting the first...

In this letter, we propose and characterize a new type of tetherless mobile microgripper for micrograsping that is made of a magnetic elastic composite material. Its magnetically-programmable material and structures make it the first three-dimensional (3D) mobile microgripper that is directly actuated and controlled by magnetic forces and torques....

At the sub-millimeter scale, capillary forces enable robust and reversible adhesion between biological organisms and varied substrates. Current human-engineered mobile untethered micromanipulation systems rely on forces which scale poorly or utilize gripper-part designs that promote manipulation. Capillary forces, alternatively, are dependent upon...

This paper presents a new method to control multiple micro-scale magnetic agents operating in close proximity to each other for applications in microrobotics. Controlling multiple magnetic microrobots close to each other is difficult due to magnetic interactions between the agents, and here we seek to control those interactions for the creation of...

We present a method to independently control two millimeter-scale soft-bodied magnetic swimmers, with nominal dimensions of 1.5 × 4.9 × 0.06 mm. A swimmer's speed depends on its relative angle with the actuation magnetic field. The two swimmers under control have different directions of net magnetic moments, and assume distinct orientations in one...

This chapter discusses the methods and state of the art in microscale manipulation in remote environments using untethered microrobotic devices. It focuses on manipulation at the size scale of tens to hundreds of microns, where small size leads to a dominance of microscale physical effects and challenges in fabrication and actuation. To motivate th...

Existing remotely actuated magnetic microrobots exhibit a maximum of only five-degree-of-freedom (DOF) actuation, as creation of a driving torque about the microrobot magnetization axis is not achievable. This lack of full orientation control limits the effectiveness of existing microrobots for precision tasks of object manipulation and orientation...

The biologically inspired strategy of distributed inward gripping (DIG) is presented in this study as a method for foot attachment and adhesion during gravity-independent climbing. As observed in nature, this strategy enables climbing animals to maneuver rapidly on surfaces in any orientation with respect to gravity, and does not require significan...

Untethered robots miniaturized to the length scale of millimeter and below attract growing attention for the prospect of transforming many aspects of health care and bioengineering. As the robot size goes down to the order of a single cell, previously inaccessible body sites would become available for high-resolution in situ and in vivo manipulatio...

This paper presents a novel synthesis method for the design of micro-scale robotic flexure mechanisms. A structural optimization method, termed the mechanism-based approach, is used to identify the optimal topology and shape of the flexure mechanisms based on their lump stiffness characteristics. Using several different fitness functions, several o...

Mobile sub-millimeter micro-robots have demonstrated untethered motion and transport of cargo in remote, confined or enclosed environments. However, limited by simple design and actuation, they lack remotely-actuated on-board mechanisms required to perform complex tasks such as object assembly. A flexible patterned magnetic material which allows in...

Remotely actuated microdevices powered by magnetic fields have gained attention where a physical presence is required inside remote or enclosed microscale environments. On page 4397, E. Diller and M. Sitti demonstrate a millimeter-scale robotic gripper capable of locomotion for precise transport, orientation, and programmable 3D assembly of micropa...

We have developed a millimeter-scale magnetically driven swimming robot for untethered motion at mid to low Reynolds numbers. The robot is propelled by continuous undulatory deformation, which is enabled by the distributed magnetization profile of a flexible sheet. We demonstrate control of a prototype device and measure deformation and speed as a...

Complex functional materials with three-dimensional micro- or nano-scale dynamic compositional features are prevalent in nature. However, the generation of three-dimensional functional materials composed of both soft and rigid microstructures, each programmed by shape and composition, is still an unsolved challenge. Here we describe a method to cod...

This manuscript presents two methods for the addressable control of multiple magnetic microrobots. Such methods could be valued for microrobot applications requiring high speed parallel operation. The first uses multiple magnetic materials to enable selective magnetic disabling while the second allows for independent magnetic forces to be applied t...

We present and compare new heat-activated bonding methods for use in modular micro-robotic systems. Such modular systems prove to provide on-demand creation of arbitrary micro-scale physical shapes in remote inaccessible spaces. The bonding methods presented here quickly form strong bonds through the use of thermoplastic or solder binding sites int...

A major challenge for untethered micro-scale mobile robotics is the control of many agents in the same workspace for distributed operation. In this work, we present a new method to independently control multiple sub-mm microrobots in three dimensions (3D) using magnetic gradient based direct pulling as the 3D motion generation method. This is accom...

To address some of the challenges in modular micro-robotics, we present a new heat-activated bonding method for assembly. This bonding method quickly forms strong bonds through the use of thermoplastic or solder binding sites integrated into each module face, addressing problems of assembly strength and electrical conductivity. The strength of the...

We present a scheme of two-dimensional module reconfiguration based on interactions between microscale magnetic modules with potential applications in micro-robotics, particularly in automatic micro-fabrication, non-invasive diagnoses, micro-surgery, and drug delivery at unreachable sites. The approach taken is a mixture of a top-down engineering a...

We present a new scheme of remote addressable magnetic actuation for sub-mm microrobotics which uses the hysteresis characteristics of multiple magnetic materials to achieve advanced state control of many magnetic actuators sharing the same magnetic control inputs. Using this standard approach, remote magnetic actuation of a single magnet has been...

We present a non-contact manipulation method for micron scale objects using locally induced rotational fluid flows created by groups of untethered magnetic micro-manipulators. The magnetic micro-manipulators are rotated in a viscous fluid by an externally generated magnetic field to create rotational flows, which act to move micro-objects in the fl...

Flagellated bacteria have been embraced by the micro-robotics community as a highly efficient microscale actuation method, capable of converting chemical energy into mechanical actuation for microsystems that require a small payload and high rate of actuation. Along with being highly motile, Serratia marcescens (S. marcescens), our bacterium specie...

Remotely and selectively turning on and off the magnetization of many micro-scale magnetic actuators could be a great enabling feature in fields such as microrobotics and microfluidics. We present an array of addressable 800 × 800 × 75 μm3 micropumps made from a composite material whose net magnetic moment can be selectively turned on or off by app...

This study develops autonomous manipulation strategies for a mobile untethered microrobot that operates on a 2-D surface in a fluidic environment. The microrobot, which is a permanent magnet, is under ${\bm 500}\, {\bm \mu }$m in all dimensions and is actuated by oscillating external magnetic fields. Two types of manipulations are considered: 1) fr...

In this paper, we propose methods to control multiple untethered magnetic microrobots (called Mag- ${\bm \mu }$Bots), with all dimensions under 1 mm, without the need for a specialized surface. We investigate sets of Mag-${\bm \mu }$ Bots that are geometrically designed to respond uniquely to the same applied magnetic fields. By controlling the mag...

A primary challenge in the field of reconfigurable robotics is scaling down the size of individual robotic modules. We present a novel set of permanent magnet modules that are under 1 mm in all dimensions, called Mag-µMods, for use in a reconfigurable micro-system. The modules are actuated by oscillating external magnetic fields of several mT in st...

In this work, we develop methods for controlling multiple untethered magnetic micro-robots (Mag-µBots) without the need for a specialized substrate. We investigate Mag-µBots that are geometrically and magnetically designed to respond uniquely to the same input magnetic fields. Designs include: (1) geometrically similar Mag-µBots with different valu...

We propose a method to increase propulsion of a micro-scale swimming robot powered by an artificial flagellum through the use of multiple helices while retaining the simple ac- tuation method of a single rotation axis. Scaled up experiments with similar Reynolds number are carried out to compare the performance of five different propulsion designs...

This work introduces new strategies for fluid-based manipulation of micro-scale objects using rotating magnetic micro-robots at low Reynolds numbers. By rapidly spinning the micro-robots, rotational fluid flow is induced which acts to move the micro-objects by fluidic drag. Acting in parallel, teams of these micro-robots are shown to work together...

In this work, we develop methods for controlling multiple untethered magnetic micro-robots (called Mag-μBots), with all dimensions under 1 mm, without the need for a specialized surface. We investigate sets of Mag-μBots that are geometrically and magnetically designed to respond uniquely to the same magnetic fields. The responses of geometrically d...

A primary challenge in the field of reconfigurable robotics is scaling down the size of individual robotic modules. We present a novel set of permanent magnet modules that are under 1 mm in all dimensions, called Mag-μMods, for use in a reconfigurable micro-system. The modules are actuated by oscillating external magnetic fields of several mT in st...

Animal behavioral, physiological and neurobiological studies are providing a wealth of inspirational data for robot design and control. Several very different biologically inspired mobile robots will be reviewed. A robot called DIGbot is being developed that moves independent of the direction of gravity using Distributed Inward Gripping (DIG) as a...

Animal behavioral, physiological and neurobiological studies are providing a wealth of inspirational data for robot design and control. Several very different biologically inspired mobile robots will be reviewed. A robot called DIGbot is being developed that moves independent of the direction of gravity using Distributed Inward Gripping (DIG) as a...

The movement capabilities of a climbing animal or robot largely depend on its attachment/detachment strategy and the workspace of its legs. Design aspects of the 18 degree-of-freedom hexapod DIGbot are presented in this work. DIGbot is named for its usage of the biologically-inspired Distributed Inward Gripping (DIG) attachment strategy to walk on...

This paper is an update on the investigation of Distributed Inward Gripping (DIG) as a rapid and robust attachment mechanism for vertical and inverted climbing. DIG is implemented on an 18-DOF hexapod, DIGbot, with onboard power and control system. Passive compliance in the foot, which is inspired by the flexible tarsus of the cockroach, increases...

A hexapod designed for wall climbing with a body joint and six 3-DOF legs can perform complex maneuvers such as sharp turns, making both interior and exterior transitions between vertical and horizontal surfaces, and traversing obstacles on both surfaces. This paper presents work toward the design and construction of the hexapod DIGbot, named for i...

Insights from biology have helped reduce the weight and increase the climbing ability of mobile robots. This paper presents Screenbot, see Fig. 1, a new 126 gram biologically-inspired robot that scales wire mesh substrates using spines. Like insects, it walks with an alternating tripod gait and maintains tension in opposing legs to keep the feet at...

Mag- Bots, short for Magnetic Micro-Robots, are mobile robots under 1 mm in all dimensions, and are actuated by electromagnetic fields. Mag- Bots are versatile in operation, capable of operating on many surfaces and within gaseous or liquid environments. They can also be used to manipulate micro-objects, both by direct contact, and in a non-contact...