One night in 2009, I was jolted awake from my sleep in the small living room by a loud thud coming from the bedroom. My mother had fallen down. It turned out she had read somewhere that keeping a night light on for long periods was very bad for sleep quality, so she had turned it off, and not wanting to switch it back on and disturb my father sleeping beside her, she had tried to negotiate her way to the bathroom using just the faint light glowing through the window. Looking at my mother’s swollen knees, I suddenly realized that my strong and wise mother, who had always been there for me when I needed help, was also weak, would also grow old. It was her tender hands that soothed my wounds when I was hurt - what could I do to return such love and care? For several days I slept fitfully, my mind obsessed with the idea of inventing a machine, a loving machine that would allow my mother to go to the bathroom every night in safety.
I was a complete mechanical novice, and so Google and electrical spare parts store owners became my sources of wisdom. When I first discovered that my setup was not working, I used a multimeter to test each connection in turn, and found that the problem was in the cold solder joint (there was an oxide film on the pin preventing the tin from sticking, which resulted in poor conduction). I googled how to fix cold solder joints, and soon learned that I needed sandpaper to remove the oxide film from the pin, and then apply a small amount of resin to the head of the electric soldering iron to solve the problem. I duly did this and tested again, but there was still no response from the relay. By this time, many of the spare parts store owners were beginning to recognize this high school student who pestered them with questions. They helped me analyze the problem and in the end suggested that I use a Darlington optocoupler to amplify the current and voltage and carry the load. However, there were thousands of optocoupler models, and no one knew which one was the best one for this situation. Having initially imagined that experimenting four or five times would be sufficient, I soon discovered that nothing I did seemed to work. And so I tried again and again, quite unconsciously making three more trips to the parts store, until on my twenty-seventh attempt, the tiny LED finally lit up. High temperatures caused by constant experimenting, sometimes for hours a day, had burned out an electric solder iron.
At last, after blistering my hands and receiving countless electric shocks, the machine was ready. It was a lovely and safe little thing: there were automatic sensors at both the head and foot of the bed, so my mother only had to step out of bed and lights embedded in the floor would flicker on, forming a trail that led all the way to the bathroom. When she returned to bed, the lights would automatically switch off, and my mother could go back to sleep in darkness. After I installed my invention at home, the next day I asked her if she was sleeping better. She smiled from ear to ear, saying she still couldn’t sleep, but now it was because she was too excited and happy to sleep.
A year and half later, that small machine has got a patent, and I am in the process of approaching big companies to arrange mass production – because the market research has been very positive, and the product is cheap and durable, it was only the problem with intellectual property rights that was holding things back. I have left my mother to study in the US. When I call her, she tells me that the little machine is working like clockwork and has never broken down, that not only has she not fallen again, but that the machine is even a comforting presence. She says that when she sees these small lights at night, she feels as if I am still at home. Now that I think about it, perhaps this is already reward enough.