Tong Lu

Date of Award

Summer 8-2016

Embargo Period


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical Engineering


Carmel Majidi


Stretchable electronics has been a rapidly developing technology which allows devices to be deformed dramatically. Compared with conventional technologies, with which devices are made of rigid materials, stretchable electronics enables devices to be stretched, twisted, and bent robustly. Such features contribute to a greater functionality and make the devices suitable for applications such as wearable devices that need to adapt to complicated geometries. Additionally, compared to conventional electronics, a wearable device that consists of stretchable electronics is safer for users. The existing materials and fabrication methods, however, lack the capability of creating practical and precise stretchable electronics rapidly at a reasonable cost. In this work, liquid metals (EGaIn, Galinstan), along with conductive polymers (cPDMS, etc), are patterned with an innovative prototyping method based on two different laser systems (CO2 and UV). With the methods developed, stretchable circuits are successfully fabricated in minutes. Experiments have been performed to show the excellent electrical properties of the laser-patterned circuits. Besides rapid prototyping, an innovative interfacing method between liquid metal and solid-state circuit components is also developed. This method is based on magnetic conductive particles embedded in polymer. The particles are aligned in a magnetic field so the composite is only conductive through its thickness. Compared with existing techniques, this method significantly enhanced the reliability of the interface between liquid metal and solid-state components and can be potentially applied on stretchable integrated circuits. A series of applications, including tactile and strain sensors, are presented to validate the developed methods.

Available for download on Thursday, July 27, 2017