Modlab The Modular Robotics Laboratory at the University of Pennsylvania



Welcome to the Modular Robotics Lab (ModLab), a subgroup of the GRASP Lab and the Mechanical Engineering and Applied Mechanics Department at the University of Pennsylvania under the supervision of Prof. Mark Yim.

A modular robot is a versatile system consisting of many simple modules that can change their configuration to suit a given task. These systems are inherently robust due to their redundancy, adaptability, and ability to self-repair. While originally focused on continuing research in the field of modular robotics, recent work at the lab has expanded to include micro/nano air vehicles, bio-inspired gaits, personal robots, and more. The ModLab is comprised of undergraduate and graduate students from multiple disciplines including mechanical, electrical, and computer systems engineering.

Featured Projects

Tactically Expandable Maritime Platform (T.E.M.P.)

We have built a system of shipping container sized robotic boats that can hook onto each other.  We demonstrate the conceptual design of a system that is capable of constructing bridges and various shaped islands that can be made compliant to waves.


The design of this system called SMORES (Self-assembling MOdular Robot for Extreme Shapeshifting) is capable of rearranging its modules in all three classes of reconfiguration; lattice style, chain style and mobile reconfiguration. Modules are independently mobile and are capable of self-assembly from a collection of disconnected modules.


The CKbot (Connector Kinetic roBot) is a chain style modular robot. It is designed to be fast and inexpensive while small enough to fit inside a 3 inch tube. It is manually reconfigurable into any shape while also allowing attachments such as wheels, grippers, IR proximity sensors and camera modules.

Recent Projects

Underactuated Rotor for Simple Micro Air Vehicles

We extract thrust, roll, and pitch authority from a single propeller and single motor through an underactuated mechanism embedded in the rotor itself. This allows new types of conventionally-capable micro air vehicles now requiring only two motors. This contrasts with the servos and linkages of conventional helicopters or the four drive motors in quadrotors.

Low-cost Laser Range Finder

The goal for this project is to make a low-cost but high-speed , very small and reliable laser range finder. The idea is to talk to a small camera, and obtain the laser line position and send out the data line by line in real-time.


Smooth motion is critical to robotic applications like haptics or those requiring high precision force control. These systems are often direct-drive, so any torque ripple in the motor output must be minimal. Unfortunately, low inherent torque ripple motors are expensive. We came up with a method to map and suppress torque ripple from cogging torque so low cost motors can perform as well as expensive ones, while using only a position sensor, which is already required for servo control. We call this compensation "Anticogging".

Passive Stability of a Single Actuator MAV

In an effort to build one of the world's smallest flying vehicles, we built a flying vehicle with only two moving parts connected by one motor. Because the vehicle cannot control its attitude with its one actuator, passive stability is a required trait, so we derived design requirements for making passively stable vehicles.


Our mobile telepresence robot is fitted with a robotic manipulator that will allow a person to virtually manipulate the avatar environment. We have shown our robot called "Persona" to be capable of moving up and down ramps, use elevators, manipulate objects such as chess pieces, and to lift and transport loads up to 4.5 kg.


The DARPA Robotics Challenge (DRC) is a competition sponsored by DARPA to encourage rapid, innovative development in the field of humanoid robotics. Modlab participated with Penn as a part of Team THOR and Dr. Lee's lab, in an alliance with Virginia Tech, Robotis Inc, and Harris Corp. The Trials were held from Dec 20-21, 2013, with sixteen teams each providing a robot to complete eight tasks designed to simulate disaster recovery scenarios.

Little Robots to move Big Things

The Little Robots to move Big Things project is motivated by the paradigm in modern robotics that most robots are incapable of manipulating objects that are even a small proportion of the robot's mass. This project seeks to overturn this trend by using small robots to create large forces by leveraging the reaction forces created through interactions with fixed objects in the workspace.


The SEAL Pack is versatile, portable, and quickly deployable, similar to the Navy SEALs.  SEAL stands for SEa, Air, and Land and the SEAL Pack is versatile enough to traverse all three.  The SEAL Pack is transported in a compact way, and can be unpacked into either a car, boat, or quadrotor in a matter of minutes thanks to its modular design.


The Modular Robotics Laboratory (Dean Wilhelmi, Stella Latscha, Matthew Piccoli) collaborated with other technology studios from Penn (IKStudio under Simon Kim) and Harvard, as well as dance studio Carbon Dance Theatre (co-choreographers: Meredith Rainey & Marcel W. Foster) to create a dance performance blending art and technology called Science Per Forms.

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