Jason Liu

Research

Biodegradable Bone Implant

A wood-based alternative to metal bone plates: densified juniper wood, crosslinked with citric acid so that it swells less in water and degrades more.

In the lab

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Two people in yellow protective suits and full-face respirators give a thumbs up, each holding a glass flask of yellow liquid.
In protective suits and respirators, holding flasks of solution in our research lab.
First-person view of a laptop with a stopwatch reading 5 hours 51 minutes, beside a protective suit hanging in the lab.
Waiting nearly six hours for the delignification treatment to finish.
A benchtop hot press with a blue base, a screw handle and a white control unit on a wooden table.
The hot press we bought to densify the treated wood.
Two students in white lab coats at a school lab bench with funnels, test tubes and yellow solutions; one gives a thumbs up.
Running the degradability test in the school lab with my research partner.
A stainless steel water bath on a hot plate with a digital temperature display, a white perforated lid with a probe through it, and a stuffed panda toy behind.
The heated bath, with its perforated lid and temperature probe.
Top view of orange-brown wood bars lying in warm yellow liquid in a steel pot.
Juniper wood soaking in citric acid solution.
Close-up of a steel mold with slotted blocks holding pieces of wood.
Pressing samples in the mold we designed.
Two people set up shelves and equipment in a bare room surrounded by open cardboard boxes.
Building the lab ourselves: unpacking equipment and assembling shelves.
Two people in yellow protective suits stand at a lab desk with an oven, with shelves of glassware and a folding chair beside them.
Black-and-white scanning electron microscope image of a rough, fibrous wood surface at x200 magnification, with a 50 micrometre scale bar.
Scanning electron microscope image of a wood sample at ×200.
A wooden desk with two open laptops showing pages of a research paper with graphs and micrographs, a notebook and sheets of handwritten notes between them, plus a cutting mat, water bottles and energy drink cans.
Writing up the research: the paper's figures on two laptops, with handwritten notes.
Labelled sample bags, each holding a small brown piece of wood, laid out in two columns.
Labelled sample bags, ready to send to an external test centre.
Two laptops on a wooden desk: one shows a page of a paper with graphs and electron micrographs, the other a spreadsheet with infrared spectra and red and blue bar charts, beside printed notes, a pen and several energy drink cans.
Spectra and bar charts on one laptop, the paper on the other.
Five labelled glass bottles with blue, white and red caps above five wooden bars in small zip bags.
Treated samples in labelled bottles and bags, ready to send to an external test centre.
Protective suits, respirators and filter cartridges, chemical gloves, nitrile gloves, wipes and boots laid out on the floor.
Safety equipment we bought before starting: protective suits, respirators, gloves and boots.
Six numbered wood bars in a heated water bath on a hot plate, with a temperature probe.
Wood in the delignification solution.
Protective gear laid out on a concrete floor: a yellow chemical suit, wipes, two half-mask respirators, blue chemical-resistant gloves, nitrile gloves, face masks, cleanroom wear and two boxed battery fans.
More safety equipment.
A person in a protective suit leans over a lab table with an oven and a laptop, handling a flask and a measuring cylinder.
Working at the bench in protective gear.

Experiment overview

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Flowchart of the experiments, from wood preparation through delignification, citric acid crosslinking and hot pressing to structural, mechanical and degradation tests.
Experiment overview: densified wood with and without citric acid crosslinking, compared by microscopy (SEM), three-point bending, infrared spectroscopy (FTIR) and degradation tests.

Results & reports

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Densified Wood: CREST Gold Award Report
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Densified Juniper Wood Crosslinked with Citric Acid: S.-T. Yau Science Award Report
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Report pages

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Two pages of a research report: the first has electron micrographs of untreated, densified and citric-acid-densified juniper wood with bar charts of volume, density and volume reduction (Figure 16) and text on swelling; the second has a grid of nine bar charts of flexural strength, maximum load and Young's modulus (Figure 17).
Report pages: microstructure and densification (Figure 16), and the mechanical properties of densified wood with and without citric acid (Figure 17).
Two more report pages: load-displacement curves for dry and swollen samples beside electron micrographs (Figure 18), and six scatter plots of strength, modulus and maximum load against delignification time.
Report pages: bending curves, surface micrographs, and how the properties change with delignification time (Figure 18).

Patent application

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Notice from China's National Intellectual Property Administration accepting a patent application, dated 27 October 2026, listing Liu Jiachen and a co-applicant as applicants and inventors, for a citric-acid-crosslinked, swelling-resistant densified wood and its preparation method and application; the red official seal is at the bottom right.
Patent application accepted by China's National Intellectual Property Administration on 27 October 2026: a citric-acid-crosslinked, swelling-resistant densified wood, with its preparation method and use.