Year/Course: 2016-2017, Easter 2017

Researcher: Dr. Sanjiv Sambandan, Lecturer, Department of Engineering
Mentor: Dr. Jessica Ocampos

Electronic printed circuit boards are ubiquitous in a world populated with digital and information technology. With few local recycling options, the aging or failure of these electronic boards contributes significantly to the generation of electronic waste (e-waste). With global population growth and an exponential increase in the consumption of electronic devices, e-waste is creating environmental crises, particularly in developing countries where much e-waste from developed countries is dumped. In emerging economies such as India, which has a significant IT industry of its own, the situation is exacerbated. For instance, each year Bangalore produces 20,000 tonnes of e-waste, and this is increasing at a rate of 20% per year. Up to 90% of this waste is handled through the informal sector in which low-paid workers sort and incinerate e-waste exposing themselves and the environment to toxins.

While electronic components will eventually age and die, prolonging their lifespan by increasing their reliability would reduce e-waste. One of the major causes of faults in printed circuit boards during operation is due to open circuits. Open circuit faults imply a disconnection of a wire carrying a signal. Such a disconnect is most commonly found in solder joints and can occur due to environmental and chemical corrosion, current spikes due to poor power supplies or electro static discharge and thermal or mechanical stress. The failure of one joint among several hundred could cause the entire board to become unusable.

Sanjiv Sambandan and his research group have identified means to heal open circuit faults and to integrate this mechanism as an add-on feature to any printed circuit board. This means that manufacturers do not have to change the way circuit boards are manufactured. Rather, a patch containing the self-healing mechanism can be added onto a printed circuit board after it is made. The mechanism is based on the use of a dispersion containing conductive microparticles in an insulating fluid. This dispersion needs to be contained over the current carrying interconnects, and the manner in which it is contained forms a part of the technology and implementation. When an interconnect experiences an open fault, the current stops flowing and a voltage develops across the gap. The corresponding electric field polarizes the particles in the fluid and these particles experience attractive forces that cause them to chain up and bridge the gap. While this technology and its implementation have been demonstrated in the lab, much work remains to develop it into an industry-friendly process.

The Development i-Team will investigate the potential of this technology to reduce the production of e-waste. The team will focus on the opportunities and challenges associated with implementing the technology to address the environmental and social problems caused by e-waste in developing and emerging economies.