Mark Cutkosky

Stanford University | SU · Department of Mechanical Engineering

We present an integrated pneumatic sensor and actuator for soft haptic devices that can estimate contact force, location, and shape using a multi-headed neural network. The sensor uses channels cast into a multi-layer silicone bubble that change flow resistance as the bubble deforms, allowing measurements of strain and external contact at the surfa...

We present the design and operation of tadpole-mimetic robots prepared for a study of the parenting behaviors of poison frogs, which pair bond and raise their offspring. The mission of these robots is to convince poison frog parents that they are tadpoles, which need to be fed. Tadpoles indicate this need, at least in part, by wriggling with a char...

Efficient control algorithms are developed to implement stiff virtual walls without chatter. An analysis of the complete coupled system comprising controller, interface device, and user’s finger underlies the design of a wall algorithm, thus each virtual wall is tailored to a specific user impedance. The finger is modeled as a static second order i...

Artificial muscles enable the design of soft implantable devices which are poised to transform the way we mechanically support the heart today. Heart failure is a prevalent and deadly disease, which is treated with the implantation of rotary blood pumps as the only alternative to heart transplantation. The clinically used mechanical devices are ass...

We present the design and operation of tadpole-mimetic robots prepared for a study of the parenting behaviors of poison frogs, which pair bond and raise their offspring. The mission of these robots is to convince poison frog parents that they are tadpoles, which need to be fed. Tadpoles indicate this need, at least in part, by wriggling with a char...

This work presents a new variation on electrostatic clutches that uses gecko‐inspired adhesives instead of friction for its braking force. As a result, it requires no power or normal pressure to remain engaged or disengaged. It requires only a brief pulse of voltage to switch states. In some applications, this capability is desirable for safety rea...

Birds are notable for their ability to seamlessly transition between different locomotory functions by dynamically leveraging their shape-shifting morphology. In contrast, the performance of aerial vehicles is constrained to a narrow flight envelope. To understand which functional morphological principles enable birds to successfully adapt to compl...

Tactile sensing is paramount for robots operating in human-centered environments to help understand interactions with objects. One challenging issue in tactile sensing is the slip detection problem. Currently, most slip detection methods use passive sensors, which only measure force or vibration, but not directly the contact area, which is one of t...

Right ventricular (RV) failure remains a significant clinical burden particularly during the perioperative period surrounding major cardiac surgeries, such as implantation of left ventricular assist devices (LVADs), bypass procedures or valvular surgeries. Device solutions designed to support the function of the RV do not keep up with the pace of d...

Soft robotic hands can facilitate human–robot interaction by allowing robots to grasp a wide range of objects safely and gently. However, their performance has been hampered by a lack of suitable sensing systems. We present a flexible and stretchable multi-modal sensor network integrated with a soft robotic hand. The design of wired sensors on a fl...

Perceiving the environment through touch is important for robots to reach in cluttered environments, but devising a way to sense without disturbing objects is challenging. This work presents the design and modelling of whisker-inspired sensors that attach to the surface of a robot manipulator to sense its surrounding through light contacts. We obta...

In this paper we present a trade study-based method to optimize the architecture of ReachBot, a new robotic concept that uses deployable booms as prismatic joints for mobility in environments with adverse gravity conditions and challenging terrain. Specifically, we introduce a design process wherein we analyze the compatibility of ReachBot's design...

This article presents a lightweight, flexible, multiaxial, and multimodal capacitive tactile sensing design for robotic or prosthetic hand manipulation. The sensor conforms readily to curved surfaces, which wrap around the back and sides of a finger. With a microstructured porous dielectric material, the sensor has a desirable combination of a wide...

A largely untapped potential for aerial robots is to capture airborne targets in flight. We present an approach in which a simple dynamic model of a quadrotor/target interaction leads to the design of a gripper and associated velocity sufficiency region with a high probability of capture. A model of the interaction dynamics maps the gripper force s...

Robotic manipulators navigating cluttered shelves or cabinets may find it challenging to avoid contact with obstacles. Indeed, rearranging obstacles may be necessary to access a target. Rather than planning explicit motions that place obstacles into a desired pose, we suggest allowing incidental contacts to rearrange obstacles while monitoring cont...

When humans socially interact with another agent (e.g., human, pet, or robot) through touch, they do so by applying varying amounts of force with different directions, locations, contact areas, and durations. While previous work on touch gesture recognition has focused on the spatio-temporal distribution of normal forces, we hypothesize that the ad...

Motion planning for a multi-limbed climbing robot must consider the robot's posture, joint torques, and how it uses contact forces to interact with its environment. This paper focuses on motion planning for a robot that uses nontraditional locomotion to explore unpredictable environments such as martian caves. Our robotic concept, ReachBot, uses ex...

Gecko-inspired adhesives can allow free-flying space robots to grasp and manipulate large items or anchor themselves on smooth surfaces. In this article, we report on the first tests conducted using gecko-inspired adhesives on a gripper attached to an Astrobee free-flying robot operating inside the International Space Station (ISS). We present resu...

Soft robotic hands can facilitate human-robot interaction by allowing robots to grasp a wide range of objects safely and gently. However, their performance has been hampered by a lack of suitable sensing systems. We present a flexible and stretchable multi-modal sensor network integrated with a soft robotic hand. The design of wired sensors on a fl...

Annuloplasty ring choice and design are critical to the long-term efficacy of mitral valve (MV) repair. DynaRing is a selectively compliant annuloplasty ring composed of variable stiffness elastomer segments, a shape-set nitinol core, and across diameter filament. The ring provides sufficient stiffness to stabilize a diseased annulus while allowing...

We present hybrid adhesive end-effectors for bimanual handling of deformable objects. The gripping system is driven by the need to achieve alignment on deformable and irregular surfaces while maintaining a large area of contact for efficient use of the adhesive. The objective of the gripping system is to reduce the internal grasping force needed to...

Right ventricular (RV) failure remains a significant burden for patients with advanced heart failure, especially after major cardiac surgeries such as implantation of left ventricular assist devices. Device solutions that can assist the complex biological function of heart muscle without the disadvantages of bulky designs and infection‐prone drivel...

FEM modelling of the incipient chip formation for the generation of micro features

This paper preliminarily explores the modeling of incipient cutting by (LS-Dyna) FEM software comparing the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is micromachining of a durable mold for mass manufacturing gecko adhesives, with challenging requirements, includi...

Our aim is to provide effective interaction with virtual objects, despite the lack of co-location of virtual and real-world contacts, while taking advantage of relatively large skin area and ease of mounting on the forearm. We performed two human participant studies to determine the effects of haptic feedback in the normal and shear directions duri...

Anthropomorphic robotic manipulators have high grasp mobility and task flexibility but struggle to match the practical strength of parallel jaw grippers. Gecko-inspired adhesives are a promising technology to span that gap in performance, but three key principles must be maintained for their efficient usage: high contact area, shear load sharing, a...

Birds take off and land on a wide range of complex surfaces. In contrast, current robots are limited in their ability to dynamically grasp irregular objects. Leveraging recent findings on how birds take off, land, and grasp, we developed a biomimetic robot that can dynamically perch on complex surfaces and grasp irregular objects. To accommodate hi...

Robots are widely deployed in space environments because of their versatility and robustness. However, adverse gravity conditions and challenging terrain geometry expose the limitations of traditional robot designs, which are often forced to sacrifice one of mobility or manipulation capabilities to attain the other. Prospective climbing operations...

We present a hydrostatic teleoperator that provides physicians remote access inside the MRI bore and enables real-time MRI guided interventions such as liver biopsies. The device consists of a custom six-axis arm and a needle insertion end effector. The manipulator is passive and backdrivable with a near one-to-one mapping of motions and forces bet...

A well-established treatment option for advanced heart failure is the implantation of a ventricular assist device (VAD) in the left heart. In over one quarter of patients, however, failure of the right ventricle (RV) occurs shortly after implantation, with a paucity of options for RV failure management in this clinical context. A possible treatment...

Fabrication techniques for gecko-inspired adhesives generally target mold durability, adhesive performance, and process efficiency and simplicity. With these goals in mind, we present a micromachining process for creating reusable aluminum molds used to fabricate directional dry adhesives. The molds require deep, narrow and overhanging grooves to c...

In the fabrication of directional gecko-inspired adhesives, a new capability made possible by the availability of metal molds is hot compression molding. This molding process allows the use of elastomers with much higher toughness than those cast at ambient temperature and pressure, as has been the common case in fabricating adhesives. In addition,...

We present a highly conformable stretchable sensory skin made of soft components. The skin uses low pressure pneumatic taxels and stretchable channels to conduct pressure signals to off-board micro-electromechanical systems (MEMS) pressure sensors. The force sensing range captures down to 0.01 N and has a roll-off of frequency of 102 Hz. Due to pre...

We present a new gripper and exploration approach that uses a finger with very low reflected inertia for probing and then grasping objects. The finger employs a transparent transmission, resulting in a light touch when contact occurs. The finger elements are stiff and mounted on precise cartesian axes for accurate proprioceptive sensing. Experiment...

Materials are traditionally tested either by imposing controlled displacements and measuring the corresponding forces, or by imposing controlled forces. The first of these approaches is more common because it is straightforward to control the displacements of a stiff apparatus and, if the material suddenly fails, little energy is released. However,...

Due to their ability to move without sliding relative to their environment, soft growing robots are attractive for deploying distributed sensor networks in confined spaces. Sensing of the state of such robots would also add to their capabilities as human-safe, adaptable manipulators. However, incorporation of distributed sensors onto soft growing r...

We present hybrid electrostatic and gecko-inspired gripping pads that help robots to lift and carry bulky objects. The directional, gecko-inspired adhesive provides a controllable shear force with low normal force, providing a very high effective coefficient of friction so that items like bags full of groceries and heavy cardboard boxes can be lift...

Assistive free-flying robots are a promising platform for supporting and working alongside astronauts in carrying out tasks that require interaction with the environment. However, current free-flying robot platforms are limited by existing manipulation technologies in being able to grasp and manipulate surrounding objects. Instead, gecko-inspired a...

We report a surface treatment for an elastomeric dry adhesive that improves adhesion, especially on surfaces with microscopic roughness. The process involves coating wedge-shaped polydimethylsiloxane (PDMS) features of the adhesive with a 50 nm coating of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). As compared to the uncoat...

We present a lightweight, low power, and compliant miniature dielectric fluid transducer intended for haptic surface display. The actuator has a large strain and fast response without an external compressor. It consists of a thin oil-filled pouch with a 1.5 mm diameter opening covered with a silicone membrane. The application of voltage causes the...

Mitral valve (MV) annular dynamics are critical to the long term efficacy of MV repair. Today’s annuloplasty rings, used to restore MV function, impose significant constraints on the motion profile of the MV annulus. We present a selectively compliant ring that provides sufficient stiffness to stabilize a diseased annulus while allowing physiologic...

We present a new tactile sensor intended for manipulation by mobile robots, for example in the home. The surface consists of an array of small, rounded bumps or "nibs", which provide reliable traction on objects like wet dishes. When the nibs contact a surface they deflect, and capacitive sensors measure the corresponding local normal and shear for...

We present a design and fabrication method using low-cost materials for a new tactile sensor that is highly stretchable (up to 60%) and for which the signal is substantially unaffected by stretching, immersion in water, or electromagnetic noise. The sensor can be wrapped around the front, side and back surfaces of fingers and allows them to flex wi...

Limited physical access to target organs of patients inside an MRI scanner is a major obstruction to real-time MRI-guided interventions. Traditional teleoperation technologies are incompatible with the MRI environment and although several solutions have been explored, a versatile system that provides high-fidelity haptic feedback and access deep in...

As robots branch out from the manufacturing sector into the home, there is a pressing need for new technology that can operate in cluttered and unstructured human environments. Loading and unloading a dishwasher serves as a difficult representative challenge for in-home robots, and a new robotic end-effector has been developed for this type of task...

We describe a process for creating durable metal molds for the fabrication of directional, gecko-inspired dry adhesives. The adhesives require microscopic inclined features with a challenging combination of tapered geometry, high aspect ratio, and smooth surface finish. Wedge-shaped features pro- duced by the new metal mold exhibit the same geometr...

Objectives: Posterior ventricular anchoring neochordal (PVAN) repair is a non-resectional technique for correcting mitral regurgitation (MR) due to posterior leaflet prolapse, utilizing a single suture anchored in the myocardium behind the leaflet. This technique has demonstrated clinical efficacy, although a theoretical limitation is stability of...

For small legged robots, ground contact interactions significantly affect the dynamics and locomotion performance. In this article, we designed thin, robust capacitive tactile sensors and applied them to the feet of a small hexapod with C-shaped rotating legs. The sensors measure contact forces as the robot traverses different types of terrain incl...

Birds land on a wide range of complex surfaces, yet it is unclear how they grasp a perch reliably. Here, we show how Pacific parrotlets exhibit stereotyped leg and wing dynamics regardless of perch diameter and texture, but foot, toe, and claw kinematics become surface-specific upon touchdown. A new dynamic grasping model, which integrates our deta...

Few technologies exist that can provide quantitative data on forces within the mitral valve apparatus. Marker-based strain measurements can be performed, but chordal geometry and restricted optical access are limitations. Foil-based strain sensors have been described and work well, but the sensor footprint limits the number of chordae that can be m...

Slip, or accidental loss, of grasped biological tissue can have negative consequences in all types of surgery (open, laparoscopic, robot-assisted). This work focuses on slip in robot-assisted surgery (RAS) with the goal of improving the quality of grasping and tool-tissue interactions. We report on a survey of 112 RAS surgeons, the results of which...

We present a hand specialized for climbing unstructured rocky surfaces. Articulated fingers achieve grasps commonly used by human climbers. The gripping surfaces are equipped with dense arrays of spines that engage with asperities on hard rough materials. A load-sharing transmission system divides the shear contact force among spine tiles on each p...

Background: Neochordoplasty is an important repair technique, but optimal anchoring position is unknown. Although typically anchored at papillary muscles, new percutaneous devices anchor the neochordae at or near the ventricular apex, which may have an effect on chordal forces and the long-term durability of the repair. Methods: Porcine mitral v...

We present a new rolling diaphragm actuator for transmitting forces in a teleoperated system. The initial application is for MR-guided biopsy procedures, providing accurate transmission of motions and forces between the fingertips of a physician and a biopsy needle being inserted into tissue. Desirable actuator qualities include low hysteresis, hig...

Surface microstructures in nature enable diverse and intriguing properties, from the iridescence of butterfly wings to the hydrophobicity of lotus leaves to the controllable adhesion of gecko toes. Many artificial analogues exist; however, there is a key characteristic of the natural materials that is largely absent from the synthetic versions-spat...

We present a capacitive sensor suitable for a gripper that uses thin films of gecko-inspired adhesives. The sensor is fabricated directly on the films and measures the area over which the adhesive makes intimate contact. In experiments, a new under-actuated gripper uses adhesive films to acquire and hold objects having a variety of shapes and textu...

In robotics, high gear reductions are often required when using an electromagnetic motor to drive revolute joints, as in a humanoid robot. Strain wave gears (SWGs), also known as harmonic drives, are often used. However, these transmissions are relatively expensive and have a fixed gear ratio. Here we present a low-cost transmission that maintains...

Gentle suction flow at the fingertips of a compliant hand can enhance object acquisition and increase the robustness of pinch grasps under water. The approach adds a low-pressure pump and flexible tubes that terminate at the distal phalanges. The light flow rate does not create a powerful suction force, nor does it stir up significant sediment. The...

Introduction: Very few technologies exist that can provide quantitative data on forces within the mitral valve apparatus. Marker based strain measurements can be performed, but chordae heterogeneity limits utility. Foil-based strain sensors have also been described, but tend to be bulky, limiting the number of chordae that can be measured. Hypothes...

Introduction: The posterior ventricular anchoring neochordal (PVAN) repair is a nonresectional, single-suture technique for correcting posterior leaflet prolapse. While this technique has demonstrated clinical efficacy, a possible limitation is the stability of the suture anchored into myocardium as opposed to the fibrous portion of a papillary mus...

Micro air vehicles (MAVs) are finding use across an expanding range of applications. However, when interacting with the environment, they are limited by the maximum thrust they can produce. Here, we describe FlyCroTugs, a class of robots that adds to the mobility of MAVs the capability of forceful tugging up to 40 times their mass while adhering to...

Design team performance is a complex phenomenon that involves person, behavior and environment parameters interacting with and influencing each other over time. In this chapter, we propose a quadratic model for team performance that allows for monitoring, improving, and reflecting on design teams at the individual, interactional and environmental l...

Grasping and manipulation of biological tissue are crucial processes during Robot-Assisted Surgery (RAS). An intelligent system that aids surgeons in maintaining a reliable, atraumatic grasp on tissue, would allow them to focus on the clinical task, and potentially improve safety and performance. To this end, we investigate slip detection of graspe...

Augmented-reality (AR) systems have been proposed for medical needle procedures as alternatives to restore the physician's natural perspective and head motion parallax that are lost when using standard imaging methods. AR systems have assumed a rigid needle, but in practice, a needle can experience large deflections which lead to significant errors...

This paper presents a method for efficiently testing the stability of an object under contact that accommodates empirical models of admissible forces at individual contact points. It handles a diverse range of possible geometries of the admissible force volume, including anisotropy, adhesion, and even nonconvexity. The method discretizes the contac...

Active sensing provides a way to assess whether a thin film of gecko-inspired adhesive has made good contact with a surface. This knowledge is useful for applications like gripping objects in space where a failed grasp could lead to loss of the object. Our active sensing approach uses Lamb waves in thin bilayers, excited, and detected by piezoelect...

This paper presents models of arrays of compliantly supported spines that attach to rough surfaces. The applications include climbing and perching robots. Surfaces are characterized in terms of asperity distributions, which lead to stochastic models of spine force capabilities over a range of loading directions. Models cover unidirectional spine ar...

As robots move beyond manufacturing applications to less predictable environments, they can increasingly benefit, as animals do, from integrating sensing and control with the passive properties provided by particular combinations and arrangements of materials and mechanisms. This realization is partly responsible for the recent proliferation of sof...

Multilayer electroactive polymer films actuate a small hand-held device that can display tool tip forces during MR-guided interventions. The display produces localized skin stretch at the thumb and index fingertips. Tests confirm that the device does not significantly affect MR imaging and produces detectable stimuli in response to forces measured...

Effective handling of delicate objects remains a challenging problem in manufacturing. Instead of using a specialized gripper or control scheme we present a solution involving gecko-inspired directional adhesives affixed to an industrial robot gripper and tactile sensor. The adhesives sustain large shear forces with very low pressure. They also rel...

Previous work has demonstrated the versatility of soft robotic grippers using simple control inputs. However, these grippers still face challenges in grasping large objects and in achieving high strength grasps. This work investigates the combination of fluidic elastomer actuators and gecko-inspired adhesives to both enhance existing soft gripper p...

This chapter seeks to identify principles that we can glean from nature regarding the design and operation of hands, and to show how they influence robotic hands and can improve their performance. The need to grasp and manipulate objects is faced by a wide range of animals, from insects to humans. The corresponding variety of solutions is immense,...

Grasping objects that are too large to envelop is traditionally achieved using friction that is activated by squeezing. We present a family of shear-activated grippers that can grasp such objects without the need to squeeze. When a shear force is applied to the gecko-inspired material in our grippers, adhesion is turned on; this adhesion in turn re...

The biomimetic replication of dry adhesion present in the gecko’s foot has attracted great interest in recent years. All the microfabrication techniques used so far were not be able to faithfully reproduce the hierarchical and complex three-dimensional geometry of the gecko’s setae, with features at the micro- and nano-scale, thus reducing the effe...

We present a new spine solution for the locomotion of human-scale robots on steep, rocky surfaces, known as linearly-constrained spines. The spine stiffness is low in the normal direction but high with respect to lateral and bending loads. The solution differs from previous spine arrays used for small robots in having a much higher spine density an...