Descriptions of sample projects are given below. Use these to select which project you would like to work on. All the projects are related to the general area of sensor technologies, which acts as a common, intellectual focus.
Once you have been admitted to the program, it is recommended that you contact the faculty member for additional information on any of these or other projects. Feel free to make arrangements with the faculty member prior to starting the SUNFEST program.
Implantable wireless touch sensors for neural prosthetics
Prof. Andrew Richardson (Neurosurgery)
Email: firstname.lastname@example.org | Website
We are developing a sensor that can be implanted under the skin, detect normal and shear forces, and wireless convey these signals to a neural prosthetic device that restores communication between body and brain after spinal cord injury. Students will learn the theory behind force transduction strategies, the principles of micromechanical system fabrication, strategies for wireless communication and powering of implantable medical devices, and techniques for directly interfacing with the brain. The students will perform compression and shear testing of sensor prototypes in tissue phantoms to quantify sensitivity to applied loads. They will also characterize the effective range of wireless data and power transmission for these prototypes.
Inverse Design for Sensing Applications
Prof. Nader Engheta (BE, ESE, MSE)
Email: email@example.com | Website
Optical Inverse Design is a numerical technique for designing structures with interesting optical properties. In traditional methods, the designer brings a combination of experience, intuition, and previous designs to bear on the problem. Typically, a handful of design parameters would then be tweaked to achieve the desired results. If the results are not achievable by varying these parameters, then the designer must guess a completely new design with new free parameters. In contrast, Inverse Design can create completely novel and surprising structures that are highly unintuitive. The student will design a sensitive optical sensor which would interrogate a subwavelength structure at a defined location at multiple wavelengths and polarizations in order to differentiate between one of several similar structures. The student will gain an understanding of optical simulation techniques, signal processing, and practical optics.
Biodegradable Sensors, Attachments, and Power Sources for Agricultural Monitoring
Prof. Mark Allen (ESE, MEAM)
A key technology enabler for widespread monitoring of agricultural fields is the ability to make sensors and associated elements that are biodegradable; i.e., that will not contribute to pollution or contamination of the agricultural environment once their functional lifetime and utility is completed. The Allen group is working on fabrication technologies for the realization of sensors, power sources, and packages based on all-biodegradable and biocompatible materials. Micromechanical structures with barbs and piercing structures for position stability20, pressure sensors capable of RF interrogation21, and biodegradable batteries and power sources22 have all been fabricated from biodegradable/biocompatible materials and large- area fabrication methods such as micromolding and lamination (Fig. 1).
Figure 1. Structures and sensors fabricated from biodegradable/biocompatible materials. (Left) Wireless pressure sensor from biodegradable polymers and metals; (Center left with inset) biodegradable battery based on Mg and NaCl; (Center right) electrochemical sensor for ion and oxygen concentration measurement based on Au and silicone;(Right) Barbed cylindrical package structure from biodegradable polymers for chaff packaging. All structures were fabricated based on large area techniques such as molding and lamination.
REU students will work to expand this technology suite to (1) encompass new biodegradable substrates; and (2) integrate new nano-based sensing materials so as to realize smart chaff suitable for crop monitoring using additional sensing schemes such as water, heat, ions, and pH. Students will not only gain appreciation for the microfabrication technologies needed to produce biologically-degradable MEMS structures and sensors, but will also gain understanding of transduction principles and measurement science in this important application realm.
Safe autonomous robots in the wild
Prof. George Pappas (ESE, CIS, MEAM)
Email: firstname.lastname@example.org | Website
Our research strives to provide safety guarantees for autonomous systems operating in unknown environments. This is accomplished by developing novel methods for semantic mapping of unknown environments (Semantic SLAM) followed by safe planning in learned environments. Our software tools leads to higher assurance autonomy that provide guarantees that integrated control loops, reasoning, and deep learning perception. Experiments can take place in the Pennovation Center described in the Facilities Section of the proposal.
Instant Gratification for Heterogeneous SoC Development
Prof. Andre DeHon (ESE, CIS)
Email: email@example.com | Website
We want to make programming today’s heterogeneous System-on-a-Chip designs (combining FPGA logic, embedded processors, and GPUs) as easy and as accessible as programming processors. Unfortunately, the current state-of-the-art is plagued by hour-long compile times for FPGAs (contrast with seconds for processors) that create a long edit-compile-debug loop that makes development less agile and disincentivizing the use and experimentation with these heterogeneous SoCs. Building on and extending emerging open-source tools, we are developing strategies to rapidly compile custom accelerators to these powerful platforms, including single-source compilation to processors and FPGAs, separate compilation and linkage, and quality-time tradeoffs. Within this agenda, there are many opporutnities for students to explore potential component tools and architectures to help realize the vision. The student will learn about modern SoC architecture and key techniques in the compilation and CAD for modern computing systems, experimental algorithm development and tuning, and software engineering.
Distributed sensing and control of reconfigurable surfaces
Asst. Prof. Cynthia Sung (MEAM, CIS)
Email: firstname.lastname@example.org | Website
The goal of this work is to create lightweight, deployable morphing structures with integrated actuation and sensing by leveraging origami (folding)-inspired approaches to design and fabrication. Folding-based assembly enables all components to be fabricated as 2D sheets, allowing us to use existing, well-established, and scalable planar fabrication processes, resulting in structures that are cheap (often <$50 in electronics and <$5 in other materials) , reliable (undergoing 10000s actuation cycles without failure) , and self-reconfigurable (via embedded smart material actuators) . Students working on the project will advance this technology by addressing (1) electronics and fabrication challenges associated with embedding a network of curvature sensors and actuators directly into the origami sheet and (2) control challenges associated with collecting and redistributing data from these distributed sensors and actuators. Current applications include jumping  and hopping  robots, as well as applications in autonomous flight and medical devices.
 Adriana Schulz, Cynthia Sung, Andrew Spielberg, Wei Zhao, Robin Cheng*, Eitan Grinspun, Daniela Rus, and Wojciech Matusik, “Interactive Robogami: An end-to-end system for design of robots with ground locomotion,” International Journal of Robotics Research, vol. 36, no. 10, pp. 1131-1147, 2017.
 Sung, Cynthia, and Daniela Rus. “Foldable joints for foldable robots.” Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021012, 2015
 Cynthia Sung, Rhea Lin*, Shuhei Miyashita, Sehyuk Yim, Sangbae Kim, and Daniela Rus, “Self-folded soft robotic structures with controllable joints,” in IEEE International Conference on Robotics and Automation, 2017, pp. 580-587.
 Carlson, Jaimie, Jason Friedman*, Christopher Kim, and Cynthia Sung. “REBOund: Untethered origami jumping robot with controllable jump height.” In IEEE International Conference on Robotics and Automation. 2020.
 Chen, Wei-Hsi, Shivangi Misra, J. Diego Caporale, Daniel E. Koditschek, Shu Yang, and Cynthia R. Sung. “A Tendon-Driven Origami Hopper Triggered by Proprioceptive Contact Detection.” In 3rd IEEE International Conference on Soft Robotics (RoboSoft), 2020, pp. 373-380.
* = undergraduate
Flexible tactile sensors and actuators for robotics
Prof. Kevin Turner (MEAM, MSE)
Email: email@example.com | Website
As robotics systems move from more specialized settings, such as the factory floor, to environments in which they interact with a broader range of objects and humans there is a growing need for new sensors to provide rich data for managing interactions between robots and the environment. In this project, the design and fabrication of flexible sensing skins that include both tactile sensors and small-scale actuators will be pursued. Arrays of low-power tactile sensors that measure normal and tangential forces at the contact surface will be realized by combining techniques from MEMS and flexible electronics. Small-scale actuators, based on thin-film piezoelectrics, will be integrated in the skins to allow for manipulation of friction and adhesion at interfaces as well active mechanical interrogation of contacts to assess mechanical properties such as stiffness. This SUNFEST project will involve sensor design, fabrication using state-of-the art facilities in the Singh Center for Nanotechnology, and benchtop testing.
Calorimetric Sensors for Agricultural Field Monitoring
Prof. Cherie Kagan (ESE, MSE, Chemistry)
Email: firstname.lastname@example.org |Website
The Kagan group is designing printable colorimetric sensors that can be distributed over the large areas of agricultural fields and are responsive to environmental changes and to the presence of pathogens for early warning of problems that threaten agricultural productivity. The colorimetric sensors are constructed from high-reflectance, plasmonic nanoantenna arrays. Most plasmonic nanoantenna arrays explored as chemical and biological sensors have been tailored to enable strong coupling between the localized surface plasmon resonance (LSPR) of the nanoantennas and the diffraction orders (or Rayleigh anomalies) of the nanoantenna array to generate sharp, hybridized resonances16 for better sensitivity. However, environmental monitoring in agricultural fields requires the design of sensors with angle-independent resonances so sensors could be distributed over fields, like ‘smart chaff’, and operate to yield accurate data on uneven soil surfaces. The Kagan group has used finite-difference time-domain simulations and top-down fabrication to establish design rules for passive, high-reflectance, and yet, angle-independent, optical sensors suitable for monitoring soil moisture.17 We then constructed optical moisture sensors by coating hydrogel on top of an ultrathin, plasmonic Au nanorod array, where the refractive index changes of the hydrogel upon exposure to moisture were transduced into spectral shifts of the resonances of the array. By decoupling the LSPR of the nanorods and the Rayleigh anomalies of the nanorod array we demonstrated colorimetric sensors with angle-independent resonances (~0.2 nm/deg). The REU student will build upon this study to make large area printed sensors by using imprinting of colloidal nanocrystal inks,18,19 and by varying the size, shape, and organization of the nanoantennas, will engineer the wavelength, amplitude and polarization-dependence of the optical response. By creating different buckets of chaff, each covered by a thin hydrogel layer of a specific composition, we will create different sensors with multiple outputs for water, temperature, pH, and ions.
Vision Based Yield Estimation
Prof. Camillo Jose Taylor (CIS)
Email: email@example.com | Website
One of the most important challenges faced by farmers is the problem of accurately estimating the amount and quality of a crop prior to harvest. This is particularly challenging for the specialty crop industry, which encompasses most crop production outside of staples such as wheat, corn and soy-beans. One promising approach that has been developed recently involves developing algorithms that can automatically analyze sensor data such as imagery to count crops such as apples, oranges and mangoes. In our laboratory we have developed techniques for counting and localizing these kinds of crops using techniques based on deep learning.23,24 Our goal in this project is to extend these techniques to handle other crops such as strawberries and blueberries that have different structures and pose different kinds of challenges.
Fabrication of transparent Ti3C2 titanium carbide electrodes for studying neural circuit dynamics
Asst. Prof. Flavia Vitale (Neurology)
Email: firstname.lastname@example.org | Website
The development of devices to record and stimulate neural circuits has led to breakthrough discoveries on the connectivity and functionality of the brain in healthy and diseased states. Though great advances have been made in implantable electrode technology, there still exists a significant trade-off between achieving high spatial resolution and scaling the devices up to monitor large brain areas. Optical recording techniques, which rely on calcium or voltage-sensitive fluorescent reporters, offer the ability to monitor thousands of individual neurons simultaneously. However, these techniques do not offer the temporal resolution necessary to decode the firing patterns of neural circuits. The combination of high temporal resolution electrophysiology recording with high spatial resolution optical recording offers the potential to study neural networks in unprecedented ways and greatly enhance neuroscience research.
The Vitale Lab is pioneering the development of neural electrode technology based on Ti3C2 titanium carbide, a recently discovered 2D nanomaterial (a.k.a. MXene) (1) with unprecedented combination of optical and electronic properties. This project will involve optimizing processing parameters including MXene solution concentration and thin-film casting procedures to create devices with a high degree of optical transparency and electrical conductivity, as our current devices are optically opaque. The student will be trained the electrode fabrication process at the Penn’s Quattrone Nanofabrication facility and will learn the basis of electrical, electrochemical and optical measurements to characterize the optical transparency, conductivity, and interface impedance of MXene films under different processing conditions. This project is intended for a student interested in learning more about neuroengineering, materials science and microfabrication.
Microfluidic systems for point of care diagnostics and high throughput processing
Prof. Haim Bau (MEAM)
The Bau lab is engaged in miniaturizing and automating clinical laboratory procedures to enable sophisticated medical diagnostics in resource poor settings, in the clinic, and at home (lab on a chip) and for genotyping (chip in the lab). Our research is interdisciplinary combining transport processes, biology, manufacturing, and mechatronics. Over the years, the Bau lab has engaged about two dozens of undergraduate students who participated in various aspects of our research, ranging from design with solid works, 3D printing, developing devices in which fluids are driven by capillary forces, and testing devices.
Magnetic Field Sensors for Brain Machine Interfaces
Asst. Prof. Troy Olsson (ESE)
Email: email@example.com | Website
The objective of this project is to build and characterize multiferroic magnetic field sensors and to evaluate the performance of these sensors in the context of brain machine interfaces (BMIs). Multiferroic devices mechanically couple a magnetostrictive material, which strains in response to magnetic fields, to a piezoelectric material, which produces output charge in response to mechanical strain. Thus, multiferroic devices can realize magnetic field sensors that produce output charge in response to magnetic fields. Multiferroic sensors operated at resonance can achieve up to 1000 times higher resolution because the strain amplitude is amplified by the mechanical quality factor. However, it is difficult to lower the resonance frequency of these sensors into the 1 Hz – 10 kHz range relevant to bioelectric signals while keeping the devices small enough for localized measurements. This project will explore the strain modulation of multiferroic devices to convert the 1 Hz to 10 kHz biopotentials into the high sensitivity and resolution band of multiferroic magnetic field sensor near mechanical resonance. The work involves designing the multiferroic material stack, including the strain actuator, designing the interface electronics and the demodulation circuitry, building the sensor, and measuring the ultimate sensitivity and resolution that can be achieved. Students will learn about magnetostrictive and piezoelectric materials and the application of magnetic field sensing to BMIs.
Designing Temperature-Responsive Materials for Sensing Local Environment
Prof. Jennifer Lukes (MEAM)
Email: firstname.lastname@example.org | Website
The idea of this project is to use computer simulations to design new temperature-responsive materials that sense the local environment and adapt their thermal properties accordingly. Such materials will be beneficial in a variety of thermal management applications, including tailorable thermal insulations and self-cooling to prevent overheating in electronics and batteries. In this project, the student will analyze how the structural configuration of a composite material can be engineered to achieve thermal self-regulation. This will be accomplished by making an initial educated guess as to the structure that will produce the desired thermal characteristics, performing theoretical modeling to calculate the thermal conductivity of this material, and iterating to find the optimal structure. This project is ideal for students who are more theoretically oriented. The student will learn about conduction heat transfer in composite materials.
Harvesting Electrical Signals from Mechanical Stimuli using Nanoporous Metal-Based Sensors and Actuators
Asst. Prof. Eric Detsi (MSE)
Email: email@example.com | Website
Nanoporous metals and their composites represent an emerging class of inorganic materials for sensing and actuation applications . The sensing and actuation mechanism in these nanoporous metals is based on their electronic charge-induced strain property. Typically, modifying the density of free electrons at the interface of a high-surface-to-volume ratio nanoporous metal gives rise to changes in the surface stress of these materials. Due to the high-surface-to-volume ratio of nanoporous metals, changes in the surface stress induces in turn detectable macroscopic reversible strains of the order of 0.1% (or higher) in the bulk of the nanoporous metal. Recently we took advantage of this concept to develop a relative humidity sensor using nanoporous Au films with high surface-to-volume ratios (see Figure 1a). This nanoporous Au-based mechanical humidity sensor was able to generate large displacements in response to changes in relative humidity as shown in Figure 1b. In addition, we have also developed an ultrasmart electrochromic composite actuator made of polyaniline (PANI) grown into the pores of nanoporous Au, which was able to undergo both dimensional changes and changes in color simultaneously as illustrated in Figure 1c. A video showing these simultaneous changes in dimension and in color is available online on the following link : https://youtu.be/yQjPHs71GLs. So far, research effort in the field of nanoporous metal-based sensors and actuators focus on the conversion of electrical energy into mechanical work. The reverse process (mechanical-to-electric energy conversion) has rarely been explored in nanoporous metals . This research is therefore aimed at harvesting electrical signals from mechanical deformations in nanoporous metal-based sensors and actuators .
Figure 1. (a) Monolithic nanoporous Au
(b) Nanoporous Au used as passive humidity sensor/actuator (c) Monolithic nanoporous Au/PANI composite used as active electrochromic actuator.  (Online supporting Video available on the following link: https://youtu.be/yQjPHs71GLs ).
 E. Detsi, Z.G. Chen, W.P. Vellinga, P.R. Onck, J.T.M. De Hosson, Actuating and Sensing Properties of Nanoporous Gold, J. Nanosci. Nanotechnol. 12 (2012) 4951–4955. doi:10.1166/jnn.2012.4882.
 E. Detsi, Z.G. Chen, W.P. Vellinga, P.R. Onck, J.T.M. De Hosson, Reversible strain by physisorption in nanoporous gold, Appl. Phys. Lett. 99 (2011). doi:10.1063/1.3625926.
 E. Detsi, P.R. Onck, J.T.M. De Hosson, Electrochromic artificial muscles based on nanoporous metal-polymer composites, Appl. Phys. Lett. 103 (2013). doi:10.1063/1.4827089.
 S.H. Kim, C.S. Haines, N. Li, K.J. Kim, T.J. Mun, C. Choi, J. Di, Y.J. Oh, J.P. Oviedo, J. Bykova, S. Fang, N. Jiang, Z. Liu, R. Wang, P. Kumar, R. Qiao, S. Priya, K. Cho, M. Kim, M.S. Lucas, L.F. Drummy, B. Maruyama, D.Y. Lee, X. Lepró, E. Gao, D. Albarq, R. Ovalle-Robles, S.J. Kim, R.H. Baughman, Harvesting electrical energy from carbon nanotube yarn twist, Science (80-. ). (2017). doi:10.1126/science.aam8771.
Understanding Grasping and Manipulation using Force Sensors
Asst. Prof. Michelle Johnson (Physical Medicine and Rehabilitation)
Email: firstname.lastname@example.org | Website
Flexible tactile feedback for Bilateral Activities of Daily Living Exercise Robot (Bi-Adler): We have developed Bi-ADLER, which is a therapy robot designed to help treat neurological disorders such as stroke and cerebral palsy. It is specifically designed for patients with upper extremity impairments, wherein one arm is impaired and the other one has higher degree of functionality. The active robot arm is mainly for supporting the impaired arm and the passive arm is controlled by the patient’s unimpaired arm. Reach and grasp is critical for patients after a stroke to relearn both unilateral or bilateral coordination for activities. Non-invasive tactile sensors that are able to provide grasp force feedback without obstructing subjects ability to grasp and sense objects are needed. We want to develop these sensors that can integrate seamlessly with the BiADLER robot to facilitate relearning after a stroke.
Non-invasive Detection of Interaction Forces During Therapy
Asst. Prof. Michelle Johnson (Physical Medicine and Rehabilitation)
Email: email@example.com | Website
There is a need for the development of non-invasive tactile sensors that can be worn on the forearm of subjects to allow researchers to measure the interaction forces being exchanged during these patient-therapist interactions during neurorehabilitation. These sensors will allow us to understand assisting forces applied during helping activities. The goal of this project is to investigate the development of such tactile sensors that are wearable, small, and invisible in that they do not interfere with the process of therapy.
Sensors for Microrobotic Systems
Asst. Prof. Mark Miskin (ESE)
Email: firstname.lastname@example.org | Website
This research project aims to build integrated sensors/actuators for microrobotic systems. Our lab has been developing actuator technologies specialized to sub 100um robots. In particular, we have found that electrochemically induced surface stresses can be used to build powerful, low-voltage actuators that can interface with electronics and have used these mechanisms to build cell-sized walking robots. Yet one of the key limitations of our current technology is its inability to sense as well as create forces. Recent experiments on macro-scale actuators have demonstrated a way forward: some electrochemical actuators exhibit “a pseudo-piezoelectric effect,” allowing both sensing and actuation. This project will apply these concepts at the microscale. Using atomic layer deposition, we will construct nanometer thick actuators made from promising actuator/sensor materials including palladium and nickel. In principle, these devices will be able to both induce and sense mechanical forces via charge transfer to a surrounding electrolyte. Students will fabricate prototype actuators, with assistance from a supervising graduate student, and perform characterization of its force-to-charge coupling. If successful, this project will enable microrobots capable of performing closed-loop control, both sensing and manipulating their world through a single, ultra- miniaturized system.
Exciton-Polariton gratings for colorimetric bio-molecular sensing
Asst. Prof. Deep Jariwala (ESE)
Email: email@example.com | Website
The objective of this project is to design nanophotonic structures in excitonic semiconductor films coupled to plasmonic or other semiconductor or epison near zero surfaces to induce narrow photonic modes that are strongly coupled to excitons. The excitonic semiconductor under question are atomically-thin transition metal dichalcogenides wherein the exciton binding energy and hence the resonance line are highly sensitive to surrounding dielectric environment. When coupled to photonic modes their sensitivity is further enhanced owing to the strong coupling between two or more oscillators and hence small change in dielectric environment either by adsorption of molecules or strain is expected to drive a large change in color visible to the naked eye as well as quantifiable via a hand held spectrometer. Students will develop skills for nanophotonic design using finite element solving softwares as well as get a change for hands on experimentation to observe color change and quantify change in reflection spectra.
Low profile, high precision torque sensor for robot arm feedback control and characterization
Prof. Mark Yim (MEAM, CIS, ESE)
Email: firstname.lastname@example.org | Website
For precision control of robot arms in conditions where they need to be safe (e.g. in the presence of humans) fast and precise torque sensors in the robot’s joints allow for precision force control. There are no low cost, low profile torque sensors that provide this job. We will scale up planar MEMS scale approaches (that can only measure small torques) to see if we can create human-scale torque sensors. Students will learn materials characterization, precision electronics and fabrication techniques.
Engineering Nontoxic Quantum Biosensors
Assoc. Prof. Lee Bassett (ESE)
Email: email@example.com | Website
Quantum mechanical systems are exquisitely sensitive to their environment. Usually this sensitivity prevents their use in biological applications, since thermal fluctuations and ambient noise can destroy quantum coherence. However, certain materials host optically active defects – so-called “impurity spins” – that exhibit quantum coherence at room-temperature and above, circumventing these limitations. The goal of this SUNFEST project is to investigate the properties of diamond nanoparticles functionalized with varied surface chemistries, towards the realization of new quantum-biochemical sensors. Nanodiamonds are inert and nontoxic, and their impurity spins respond to nanoscale magnetic and electrochemical fields through optical signals. The student will study the effects of different chemical and electrochemical environments on the nanoparticles’ optical response. In the process, they will gain varied experimental skills and work as part of an interdisciplinary team involving physicists, biochemists, and electrical engineers.
Robots for River and Ocean Monitoring
Assoc. Prof. M. Ani Hsieh (MEAM)
Email: firstname.lastname@example.org | Website
Robots are critical tools in the stewardship of our water resources. Our research focuses on developing new robotic algorithms and platforms for robots to better sample and monitor marine environments. In particular, we focus on developing mapping, estimation, and control strategies that allow robots to harness the environmental dynamics for motion, planning, control, and coordination. Our strategies result in more energy efficient navigation strategies for marine vehicles and improved environmental models needed for water quality assessment and flow prediction. In our work, we synthesize ideas from robotics, nonlinear dynamics, and fluid dynamics in our design of planning, control, and coordination strategies for single and teams of robots. We experimentally validate our systems using our indoor multi-robot flow tank facilities and on the Schuylkill River using our autonomous boats.
June 1 – August 6, 2021
February 1, 2021