Creative Learning: Forensic Botany Class Goes from Science to Sculpture

In the University of Wisconsin-Madison (UW) Department of Botany’s Forensic Botany class, Forest Products Laboratory (FPL) research botanist Alex Wiedenhoeft gives his students full creative license when it comes to their final projects.

“They could even do an interpretive dance.” said Wiedenhoeft, “Although they’d have to interpret it for me, since I’m a botanist.”

Undergraduate student Jennifer Baccam appreciated the freedom of the assignment and chose an interesting medium to demonstrate what she had learned in Wiedenhoeft’s class: sculpture.

Jennifer Baccam’s sculpture of FPL’s Arthur Koehler.

Baccam is majoring in plant biology and when she heard about Wiedenhoeft’s forensic botany class, her curiosity was piqued.

“I love botany and have done lots of field work,” said Baccam. “This class seemed like an interesting way to meet the requirement of taking a laboratory class.”

In giving thought to her final project, Baccam wanted to know how forensic botany came about. When she began to research the topic, Baccam discovered it all began with a scientist named Arthur Koehler from none other than the Forest Products Laboratory.

Koehler was the chief wood technologist at FPL in 1932 when Charles Lindbergh’s infant son was kidnapped and a wooden ladder was nearly the only evidence at the scene of the crime. Koehler was asked to participate in the investigation and eventually testified in the trial. Based partly on Koehler’s testimony, Bruno Hauptmann was convicted of the crime, and subsequently executed.

At the time, no one had heard of an expert witness in wood. In fact, one of Hauptmann’s lawyers stated the following in objection to a question posed to Koehler: “We say that there is no such animal known among men as an expert on wood; that it is not a science that has been recognized by the courts; that it is not in a class with handwriting experts or with ballistic experts. But this is no science, this is merely a man who has had a lot of experience in examining trees, who knows the barks on trees and a few things like that.”

Koehler of course balked at this statement, and it was stricken from the record as the court deemed Koehler was indeed “qualified as an expert upon the subject matter.”

As Baccam read Koehler’s testimony, she found it plenty apparent that he was confident in his skills and abilities as a wood expert, and he stood behind what he had learned in examining the ladder as evidence.

Forensic Botany student Jennifer Baccam.

“Koehler came across as a larger-than-life personality,” said Baccam. This observation is apparent in her sculpture, in which Koehler’s bust is looming over the other aspects of the case that are represented, including the ladder itself.

Baccam’s curiosity about forensic botany continues to lead her down a new path, as she is set to begin working in FPL’s Center for Wood Anatomy Research with Wiedenhoeft soon, and will complete her senior thesis at FPL beginning in the fall.

“I’m lucky to have Alex as my mentor,” says Baccam. “Since the beginning of the Forensic Botany course he has helped me further realize that research is truly my passion. My perspective of my future is much less uncertain now.”

To learn more about Wiedenheoft’s forensic botany course, which he co-teaches with UW Professor Sara Hotchkiss, see this feature story from UW-Madison.

‘Shocking’ Discovery: Nanocellulose Can Turn Footsteps into Electricity

Many exciting developments have resulted from the Forest Products Laboratory (FPL) and the University of Wisconsin (UW) working together to find applications for nanocellulose. From computer chips made of wood to aerogels that could clean up oil spills, the technologies researchers dream up are fascinating.

This week, yet another discovery from this FPL/UW collaboration was unveiled: flooring that converts footsteps to usable energy.

The following is a press release from the UW on this newest development in the world of nanocellulose.


Move over, solar: The next big renewable energy source could be at our feet

Flooring can be made from any number of sustainable materials, making it, generally, an eco-friendly feature in homes and businesses alike.

Now, flooring could be even more “green,” thanks to an inexpensive, simple method developed by University of Wisconsin-Madison materials engineers that allows them to convert footsteps into usable electricity.

Associate Professor Xudong Wang holds a prototype of the researchers’ energy harvesting technology, which uses wood pulp and harnesses nanofibers. The technology could be incorporated into flooring and convert footsteps on the flooring into usable electricity. Credit: Stephanie Precourt/UW-Madison

Associate Professor Xudong Wang holds a prototype of the researchers’ energy harvesting technology, which uses wood pulp and harnesses nanofibers. The technology could be incorporated into flooring and convert footsteps on the flooring into usable electricity. Credit: Stephanie Precourt/UW-Madison

Xudong Wang, an associate professor of materials science and engineering at UW-Madison, his graduate student Chunhua Yao, and their collaborators published details of the advance Sept. 24 in the journal Nano Energy.

The method puts to good use a common waste material: wood pulp. The pulp, which is already a common component of flooring, is partly made of cellulose nanofibers. They’re tiny fibers that, when chemically treated, produce an electrical charge when they come into contact with untreated nanofibers.

When the nanofibers are embedded within flooring, they’re able to produce electricity that can be harnessed to power lights or charge batteries. And because wood pulp is a cheap, abundant and renewable waste product of several industries, flooring that incorporates the new technology could be as affordable as conventional materials.

While there are existing similar materials for harnessing footstep energy, they’re costly, nonrecyclable, and impractical at a large scale.

Wang’s research centers around using vibration to generate electricity. For years, he has been testing different materials in an effort to maximize the merits of a technology called a triboelectric nanogenerator (TENG). Triboelectricity is the same phenomenon that produces static electricity on clothing. Chemically treated cellulose nanofibers are a simple, low-cost and effective alternative for harnessing this broadly existing mechanical energy source, Wang says.

The UW-Madison team’s advance is the latest in a green energy research field called “roadside energy harvesting” that could, in some settings, rival solar power — and it doesn’t depend on fair weather. Researchers like Wang who study roadside energy harvesting methods see the ground as holding great renewable energy potential well beyond its limited fossil fuel reserves.

“Roadside energy harvesting requires thinking about the places where there is abundant energy we could be harvesting,” Wang says. “We’ve been working a lot on harvesting energy from human activities. One way is to build something to put on people, and another way is to build something that has constant access to people. The ground is the most-used place.”

Heavy traffic floors in hallways and places like stadiums and malls that incorporate the technology could produce significant amounts of energy, Wang says. Each functional portion inside such flooring has two differently charged materials — including the cellulose nanofibers, and would be a millimeter or less thick. The floor could include several layers of the functional unit for higher energy output.

“So once we put these two materials together, electrons move from one to another based on their different electron affinity,” Wang says.

The electron transfer creates a charge imbalance that naturally wants to right itself but as the electrons return, they pass through an external circuit. The energy that process creates is the end result of TENGs.

Wang says the TENG technology could be easily incorporated into all kinds of flooring once it’s ready for the market. Wang is now optimizing the technology, and he hopes to build an educational prototype in a high-profile spot on the UW-Madison campus where he can demonstrate the concept. He already knows it would be cheap and durable.

“Our initial test in our lab shows that it works for millions of cycles without any problem,” Wang says. “We haven’t converted those numbers into year of life for a floor yet, but I think with appropriate design it can definitely outlast the floor itself.”

The Wisconsin Alumni Research Foundation holds the patent to the technology. Other authors on the paper include Zhiyong Cai of the Forest Products Laboratory and UW-Madison graduate students Alberto Hernandez and Yanhao Yu. The Forest Products Laboratory and National Science Foundation provided funding for the research.

—Will Cushman


Partners In Crime: Forensic Botany Current Focus of Century-Old Collaboration

Students in the University of Wisconsin-Madison (UW) Department of Botany’s Forensic Botany class recently toured the Center for Wood Anatomy Research (CWAR) at the Forest Products Laboratory (FPL). The tour is just a part of the latest collaboration between the two, which have partnered in various ways for nearly a century.

“This was an opportunity for the students to take a peek at the dirty white underbelly of scientific research, and see what a wood anatomy lab looks like,” said Alex Wiedenhoeft, Research Botanist and Team Leader in the CWAR, and one of the Botany Department professors co-teaching the course.

FPL's Alex Wiedenhoeft addresses a UW-Madison Forensic Botany class.

FPL’s Alex Wiedenhoeft addresses a UW-Madison Forensic Botany class.

Wiedenhoeft and his CWAR research team showed the students a range of projects, from botanical wood anatomy exploring the evolution of plant form, to the nuts and bolts of ongoing forensic wood science research.  “We’re using their exposure to the realities of wood research as a backdrop for their capstone laboratory work in the class, where they will divide into teams, experts for the prosecution and defense, and work together to complete a forensic wood analysis,” said Wiedenhoeft.

He won’t divulge what cases the students will solve, but Wiedenheoft indicated that one is a civil case involving alleged wood species substitution.  He won’t even hint at the criminal case.  (A note of reassurance if the thought of botanists-in-training tackling legal cases makes you nervous: “These cases are completely fictional,” Wiedenhoeft said, ensuring that no ongoing real-world cases could be jeopardized.)

At first glance, courses in forensic botany or forensic wood science may look like a novelty, but the CWAR and the UW have a long history of working together on forensic matters, from questions about the kind of wooden stick found in a plastic bottle to plant material as a feedstock for the synthesis of illegal drugs. (There was even a joint investigation into possible wood evidence from a famous serial killer, but we’ll save that story for another blog post.)

 A Historic Collaboration

Eloise Gerry

Eloise Gerry made the first connection between the UW and FPL’s CWAR.

The CWAR and the UW Department of Botany have a nearly a century’s history of interaction.  The first and most obvious place they come together is in academic lineages for CWAR leadership, which go back at least to the 1920’s. The first Project Leader of the CWAR, and the first female scientist in the Forest Service, Eloise Gerry, earned her Ph.D. in the UW Departments of Botany and Plant Pathology in 1921.

Several decades pass with no recorded affiliations, then Robert Koeppen became a student of legendary former UW Herbarium Director Hugh Iltis.  Koeppen went on to be Project Leader of the CWAR from 1975-1980.   The next Project Leader in the CWAR succession (1980-2005), Regis Miller, had been a Master’s student of the UW’s Ray Evert in the 1960s and also became an Adjunct Professor of Botany at the UW.

The current Team Leader for the CWAR, Alex Wiedenhoeft, was an undergraduate student of Ray Evert, earned both his M.S. and Ph.D. in Botany with Paul Berry, and now is an Adjunct Assistant Professor in the Department.  All senior staff in the CWAR have some official appointment within the Department. Research Botanist Michael Wiemann is an Honorary Fellow affiliated through Ken Cameron.  Rafael Arévalo and Adriana Costa are Honorary Fellows affiliated through Wiedenhoeft, and are also working in his lab as postdocs.

Internships for Botany Department students, undergraduate and graduate, have been an important part of CWAR’s contact and interaction with the UW.  Alumni of CWAR student programs include Wiedenhoeft (B.S., M.S., Ph.D. –Berry), Terra Theim (B.S., Ph.D.-Givnish), Deniz Aygoren (M.S. -Cameron), Brian Sidoti (Ph.D. -Cameron), Rafael Arévalo (Ph.D.-Cameron), and Giovanny Giraldo (current Ph.D. student – Cameron).

The two institutions have another historic guest relationship – lectures on wood anatomy and wood identification in Sara Hotchkiss’ Dendrology and Marisa Otegui’s Plant Anatomy classes.  Now, Wiedenhoeft and Hotchkiss have teamed up to develop and teach Forensic Botany.  Arévalo presented a guest lecture on plant poisons in the course, and Costa has assisted in developing the hands-on laboratory activities.

The CWAR and UW Department of Botany have a reciprocal history in scientific collections, as well. In the early 2000s, the CWAR herbarium (MAD) was transferred on permanent loan to the Department’s Wisconsin State Herbarium (WIS) facility, thanks in large part to a facilities grant awarded to house this collection in new compacting cabinets.  A few years later, Ray Evert transferred the Katherine Esau and Vernon Cheadle phloem microscope slide collection to the CWAR, where it is now housed and accessioned.  In this way, MAD is a permanent guest of the UW, as the slide collection is of the CWAR.

The xylarium, or collection of wood specimens, at the Forest Products Laboratory.

The xylarium, or collection of wood specimens, at the Forest Products Laboratory.

Looking to the Future

With the growth in CWAR research program in the last several years and a new level of cooperation between the UW Department of Botany and CWAR, opportunities for future collaboration are growing in basic and applied research, as well as collections management and curation.

Community engagement and outreach, especially in the coming years, is another area where the groups work together and share common goals.  Staff want to bring science to the people, and seek to inspire kids to ask questions about the natural world, and to think seriously about careers in STEM-related fields. Because the CWAR and the Botany Department share similar goals in their desire for outreach, staff worked together to translate their passion for, and the relevance of, plant research to a module about tree growth, wood evolution, and wood anatomy. This development improves public access to basic plant science research and information.

Through continued work with the UW Department of Botany, CWAR is looking forward to building a new foundation for the next century of collaboration.

Blog post by Alex Wiedenhoeft, Rafael Arévalo, Adriana Costa, and Rebecca Wallace