Scientists from Nanyang Technological University (NTU) have successfully printed complex electronic circuits by using a common t-shirt printer. The electronic circuits are printed utilizing special materials as a part of layers on top of regular flexible materials, for example, plastic, aluminum foil and paper.

Non-toxic materials such as silver nanoparticles, carbon and plastics are utilized to print the key segments of a complex electronic circuit, namely resistors, transistors and capacitors. Associate Professor Joseph Change, who headed the NTU research group, said their novel printing approach has now made large scale manufacturing of cheap disposable electronic circuits an attainable feat.

The electronics wizard from NTU’s School of Electrical and Electronic Engineering believes the unique technique will bring smarter products into the consumer goods market. For example, a milk carton that lets you know precisely when the milk expires, a band-aid that prods you when it is time for a redressing, or smart patches that can screen life signals such as heart rate.

So far, the team has successfully printed a few complex circuits. Amongst those includes a 4-bit digital-to-analog converter – a unit generally used in turning digital signals into sound for speakers and headphones; and radio-frequency identification (RFID) tags, normally used for tracking merchandise.

The fundamental difference between Prof Chang's technique and other alternatives of printed electronics is that it is completely cumulative, which makes it exceptionally eco-friendly. The circuits are printed without the using of any dangerous chemicals or oxidizing agents available in the market.

Prof Chang chimes in that the basic motto behind this was to make the entire production process greener by using non-corrosive chemicals. The electronic circuits can be printed on demand when required within a time frame of few minutes. It is additionally adaptable and can be used to print large circuits on different types of materials. Lastly, the innovative technique is low cost, since the print technology isn’t avant-garde and has been there in the market since decades.

The unique printing technology spearheaded by NTU has brought about two provisional patents and research papers in a few scientific publications, which also includes one of the second most downloaded in Sciencedirect, a database of 2,500 journals. Of the two patent licenses, one is on a cheap disposable Internet-of-Things for Drug Medication Adherence.

A start-up company is being established by the four-person multidisciplinary team comprising of two engineers, a material scientist and a chemist. A venture capitalist has already expressed interested towards funding for the commercialization of this technology, in addition to a multinational biomedical company, which also seems to be interested into embracing the application of printed electronics for its biomedical devices.

The research project was funded jointly by NTU, the Agency for Science Technology and Research, Science and Engineering Research Council and the Ministry of Education Singapore.