  Printed electronics is quickly emerging with tremendous value in a wide
variety of latest electrical engineering areas. However, restricted to the
rather limited conductive inks and printing strategies, the currently existing
electronics manufacturing tools are generally complicated, expensive, time,
material, water and energy consuming, and thus mainly restricted to the
industrial use. Here from an alternative way, the present article demonstrated
for the first time an entirely automatic printing system for personal
electronics manufacturing through introducing a composite liquid metal ink
delivery and printing mechanism to overcome the large surface tension facing
the solution, and integrating it with the notebook computer controlling
algorithm. With the developed printer, any desired electronically conductive
patterns spanning from single wires to various complex structures like
integrated circuit (IC), antenna, PCB, RFID, electronic greeting cards,
decoration arts, classical buildings (White House, Great Wall etc.) or more
do-it-yourself (DIY) circuits were demonstrated to be printed out in a moment
with high precision. And the total cost for the whole system has reached
personal affordability, which is hard to offer by so far the state of the art
technologies. Some fundamental fluid dynamics mechanisms related to the
proposed tapping mode enabled reliable printing and adhesion of the liquid
metal electronics on the flexible substrate was systematically disclosed
through theoretical interpretation and experimental measurements. This clearly
beyond-the-lab technology and pervasively available liquid metal printer opens
the way for large scale home level electronics making in the coming time.
