Biological engineering personal statement example

Personal statement example

On Saturdays I work in the aquatics section of a garden centre, and the question customers ask most is why their pond or tank has turned green. Usually the answer involves too much light, too many nutrients and not enough circulation, and I have become fairly good at explaining it with a test kit and a sketch on the back of a receipt. What started to interest me, though, was that the shop staff judged water quality almost entirely by eye. I wanted to know whether something as simple as cloudiness could be measured cheaply and reliably, and that question became the project I have spent most of this year on.

Using an Arduino, an LED and a light-dependent resistor, I built a basic turbidity sensor that clips onto a glass jar. I grew green algae from a pond sample in jars on my bedroom windowsill, some with a pinch of plant fertiliser and some without, and logged readings twice a day for three weeks. The first version was badly affected by daylight leaking in, so I made a cardboard shroud and took readings at fixed times. To calibrate it I diluted milk in known proportions, which gave me a curve I could convert readings against. The results were rough, but the fertilised jars clouded noticeably faster, and the growth curves had the lag, steep rise and levelling-off shape we had studied in Biology. Seeing a textbook graph emerge from my own messy data was satisfying, and it made me think harder about what limits growth in a closed system.

That project pulled together my three A levels in a way I had not expected. Chemistry gave me the vocabulary for nitrates and phosphates, and our practical on rates of reaction made me more careful about controlling variables. In Maths, fitting my data to an exponential model during the growth phase showed me why logarithms are useful rather than just something to rearrange. Biology supplied the organisms and the questions. Biological engineering appeals to me because it treats living systems as things you can measure, model and design around, which is what I was attempting at a very small scale.

Outside school reading, I worked through parts of Adam Rutherford's Creation, which explains synthetic biology for a general reader. His account of engineering microbes to produce useful compounds made me realise that the growth curves I was plotting matter enormously when the goal is a product and not just a cloudy jar. I have also watched recorded university lectures on bioreactor design, and while much of the mathematics was beyond me, I followed the central idea that oxygen transfer and mixing can limit growth as much as nutrients do. That linked straight back to circulation in fish tanks.

My job has taught me other things too. I handle stock deliveries, keep the till balanced at the end of shifts and help train newer Saturday staff on testing water for customers. Explaining nitrite readings to someone worried about their fish has made me better at turning technical information into practical advice without talking down to people.

I also play bass in a covers band with friends. We rehearse in a garage on Sunday afternoons and have played a few local pubs and a school fundraiser. It has nothing to do with algae, but it has taught me to turn up prepared, listen to other people and keep going when something goes wrong mid-song.

I know my sensor would not survive scrutiny in a real laboratory, and that is partly why I want to study this subject properly. I want to learn the fluid mechanics, thermodynamics and molecular biology that would let me design something that works reliably rather than just well enough on a windowsill. I am patient with repetitive measurement, I enjoy building things, and I am keen to find out how far careful engineering can take a biological idea.