Madden, John

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Research Interests

• Artificial Muscle and Application to Medical Devices;
• Photosynthetic Photovoltaics
• Super-Capacitors
• Batteries
• Sensors
• Carbon Nanotube Devices

Research Projects

• Soft Tactile Sensors: A transparent stretchable touch sensor based on low cost stretchable gel ionic conductors and silicone materials was developed, towards wide applications in soft robotic skin, wearables, and flexible consumer electronics. Transparent tactile sensors based on metal and carbon conductive materials can operate while bent, while our device demonstrates sensitivity to even finger proximity during active bending and stretching. The projected electric field above the sensor couples with and senses a finger. The movement of a finger a few centimeters above the surfaces can be tracked across the array and the approach is adaptable to the detection of proximity, touch and pressure over a wide variety of surface conformations.
• Conducting Polymer Actuators: Conducting polymers, such as PEDOT and Polypyrrole (PPy), feature a combination of properties such as bio-compatibility, low density, low operating voltage, high work density, and scalability, which makes them promising for use in medical, tactile feedback and other applications.In particular, the combination of low voltage (< 2V) and large strain (> 1%) distinguishes these actuators from piezoelectrics and electrostatic actuators. With the aim of paving the way to employ fast conducting polymer actuators in real applications, we developed a new fabrication process for these electro-chemical devices, demonstrated an effective process for their encapsulation, and created a web-based graphical user-interface tool to facilitate their modeling and design optimization for different applications.
• Stretchable Batteries: In an era of advanced computing and global connectivity, if wearable devices are to provide the range of comfort and flexibility users expect, they will require functional energy storage devices that are capable of undergoing various mechanical deformations. Molecular Mechatronics lab researchers have now revealed noteworthy advances on that front. Taking advantage of polymer material properties, the team has developed simple and scalable methods for fabrication of washable and stretchable batteries. Providing safety and comfort, these batteries can be integrated into smart wearables and a variety of flexible electronics, while maintaining their energy capacity levels throughout multiple stretch – strain cycles. Further advances are underway to enhance the mechanical and chemical performance of the developed technology.